image
imagewidth (px)
53
760
question
stringlengths
14
862
choices
sequencelengths
2
5
answer
int8
0
4
hint
stringlengths
0
1.85k
task
stringclasses
3 values
grade
stringclasses
12 values
subject
stringclasses
3 values
topic
stringclasses
26 values
category
stringclasses
119 values
skill
stringclasses
321 values
lecture
stringclasses
256 values
solution
stringlengths
0
2.72k
Complete the text to describe the diagram. Solute particles moved in both directions across the permeable membrane. But more solute particles moved across the membrane (). When there was an equal concentration on both sides, the particles reached equilibrium.
[ "to the right than to the left", "to the left than to the right" ]
1
The diagram below shows a solution with one solute. Each solute particle is represented by a yellow ball. The solution fills a closed container that is divided in half by a membrane. The membrane, represented by a dotted line, is permeable to the solute particles. The diagram shows how the solution can change over time during the process of diffusion.
closed choice
grade6
natural science
chemistry
Solutions
Diffusion across membranes
In a solution, solute particles move and spread throughout the solvent. The diagram below shows how a solution can change over time. Solute particles move from the area where they are at a higher concentration to the area where they are at a lower concentration. This movement happens through the process of diffusion. As a result of diffusion, the concentration of solute particles becomes equal throughout the solution. When this happens, the solute particles reach equilibrium. At equilibrium, the solute particles do not stop moving. But their concentration throughout the solution stays the same. Membranes, or thin boundaries, can divide solutions into parts. A membrane is permeable to a solute when particles of the solute can pass through gaps in the membrane. In this case, solute particles can move freely across the membrane from one side to the other. So, for the solute particles to reach equilibrium, more particles will move across a permeable membrane from the side with a higher concentration of solute particles to the side with a lower concentration. At equilibrium, the concentration on both sides of the membrane is equal.
Look at the diagram again. It shows you how the solution changed during the process of diffusion. Before the solute particles reached equilibrium, there were 3 solute particles on the left side of the membrane and 5 solute particles on the right side of the membrane. When the solute particles reached equilibrium, there were 4 solute particles on each side of the membrane. There was 1 more solute particle on the left side of the membrane than before. So, for the solute particles to reach equilibrium, more solute particles must have moved across the membrane to the left than to the right.
What is the name of the colony shown?
[ "Vermont", "New York", "Connecticut", "Virginia" ]
1
closed choice
grade5
social science
us-history
English colonies in North America
Identify the Thirteen Colonies
The colony is New York. During the colonial era, New Hampshire and New York both claimed the territory that would later become the state of Vermont. Vermont was never its own colony.
Not supported with pagination yet
What information supports the conclusion that Brandon inherited this trait?
[ "Brandon's parents have blond hair. They passed down this trait to Brandon.", "Brandon's mother cuts his hair every month." ]
0
Read the description of a trait. Brandon has blond hair.
closed choice
grade3
natural science
biology
Heredity
Inherited and acquired traits: use evidence to support a statement
Organisms, including people, have both inherited and acquired traits. Inherited and acquired traits are gained in different ways. Inherited traits are passed down through families. Children gain these traits from their parents. Inherited traits do not need to be learned. Acquired traits are gained during a person's life. Some acquired traits, such as riding a bicycle, are gained by learning. Other acquired traits, such as scars, are caused by the environment.
Which of the following was an independent variable in this experiment?
[ "the size of each dough ball", "the temperature where the dough was left to rise" ]
1
The passage below describes an experiment. Read the passage and think about the variables that are described. Michelle was learning to bake bread at home. Her first few batches of dough did not rise, or expand, as much as they should have. Michelle's mother noted that the kitchen was cold and suggested that the dough might not be warm enough to rise. Michelle decided to test her mother's suggestion. She made a large batch of dough and divided it into six equal-sized balls. Then, she put each ball into a bowl. She left three bowls on the counter in the kitchen, where the temperature was 63°F. She left the other three bowls on her desk in her upstairs bedroom, where the temperature was 80°F. After one hour, Michelle measured the size of each dough ball. Hint: An independent variable is a variable whose effect you are investigating. A dependent variable is a variable that you measure. Figure: bread dough left in a bowl to rise.
closed choice
grade6
natural science
science-and-engineering-practices
Designing experiments
Identify independent and dependent variables
Experiments have variables, or parts that change. You can design an experiment to find out how one variable affects another variable. For example, imagine that you want to find out if fertilizer affects the number of tomatoes a tomato plant grows. To answer this question, you decide to set up two equal groups of tomato plants. Then, you add fertilizer to the soil of the plants in one group but not in the other group. Later, you measure the effect of the fertilizer by counting the number of tomatoes on each plant. In this experiment, the amount of fertilizer added to the soil and the number of tomatoes were both variables. The amount of fertilizer added to the soil was an independent variable because it was the variable whose effect you were investigating. This type of variable is called independent because its value does not depend on what happens after the experiment begins. Instead, you decided to give fertilizer to some plants and not to others. The number of tomatoes was a dependent variable because it was the variable you were measuring. This type of variable is called dependent because its value can depend on what happens in the experiment.
Not supported with pagination yet
What can seeds look like?
[ "Seeds are always round and black.", "Seeds are always small and flat.", "Seeds can come in many shapes, colors, and sizes." ]
2
closed choice
grade4
natural science
biology
Plants
Describe and construct flowering plant life cycles
Many plants have flowers. These plants can use their flowers to reproduce, or make new plants like themselves. How do plants use their flowers to reproduce? First, the male part of the flower makes pollen, and the female part makes eggs. Animals, wind, or water can move pollen. Pollination is what happens when pollen is moved to the female part of the flower. After pollination, sperm from the pollen can combine with the eggs. This is called fertilization. The fertilized eggs grow into seeds. The fruit grows around the seeds. Later, a seed can fall out of the fruit. It can germinate, or start to grow into a new plant.
Seeds can be big or small. This coconut seed is big. Seeds can be many different shapes. These maple seeds are long and flat. Seeds can be many different colors. These mustard seeds are yellow.
What is the capital of Arizona?
[ "Tucson", "Cheyenne", "Carson City", "Phoenix" ]
3
closed choice
grade3
social science
geography
State capitals
Identify the 50 state capitals
Phoenix is the capital of Arizona.
Which solution has a higher concentration of blue particles?
[ "Solution A", "neither; their concentrations are the same", "Solution B" ]
2
The diagram below is a model of two solutions. Each blue ball represents one particle of solute.
closed choice
grade8
natural science
chemistry
Solutions
Compare concentrations of solutions
A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent
In Solution A and Solution B, the blue particles represent the solute. To figure out which solution has a higher concentration of blue particles, look at both the number of blue particles and the volume of the solvent in each container. Use the concentration formula to find the number of blue particles per milliliter. Solution B has more blue particles per milliliter. So, Solution B has a higher concentration of blue particles.
Which country is highlighted?
[ "Australia", "the Marshall Islands", "Papua New Guinea", "New Zealand" ]
2
closed choice
grade8
social science
geography
Oceania: geography
Identify and select countries of Oceania
This country is Papua New Guinea. Why does Papua New Guinea share its island with another country? Papua New Guinea takes up the eastern half of the island of New Guinea. The western half is part of Indonesia, an Asian country. Beginning in the 17 th century, several countries took control of different parts of the island of New Guinea. By 1922, Australia controlled the entire eastern half of the island, and the Netherlands controlled the western half. In 1963, control over the western half was transferred to Indonesia, which had just gained independence from the Netherlands. Many people in western New Guinea did not want to become part of Indonesia, though, and some people in this area are still fighting to leave Indonesia today. The eastern part gained independence from Australia in 1975 and became Papua New Guinea.
What is the name of the colony shown?
[ "Connecticut", "New York", "Massachusetts", "Tennessee" ]
2
closed choice
grade8
social science
us-history
Colonial America
Identify the Thirteen Colonies
The colony is Massachusetts. The Massachusetts Colony included land that would later become the state of Maine. Maine was never its own colony.
Which of the following could Elise and Myra's test show?
[ "if the concrete from each batch took the same amount of time to dry", "if a new batch of concrete was firm enough to use" ]
1
People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design. The passage below describes how the engineering-design process was used to test a solution to a problem. Read the passage. Then answer the question below. Elise and Myra were making batches of concrete for a construction project. To make the concrete, they mixed together dry cement powder, gravel, and water. Then, they checked if each batch was firm enough using a test called a slump test. They poured some of the fresh concrete into an upside-down metal cone. They left the concrete in the metal cone for 30 seconds. Then, they lifted the cone to see if the concrete stayed in a cone shape or if it collapsed. If the concrete in a batch collapsed, they would know the batch should not be used. Figure: preparing a concrete slump test.
closed choice
grade6
natural science
science-and-engineering-practices
Engineering practices
Evaluate tests of engineering-design solutions
People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design. How can you determine what a test can show? You need to figure out what was tested and what was measured. Imagine an engineer needs to design a bridge for a windy location. She wants to make sure the bridge will not move too much in high wind. So, she builds a smaller prototype, or model, of a bridge. Then, she exposes the prototype to high winds and measures how much the bridge moves. First, identify what was tested. A test can examine one design, or it may compare multiple prototypes to each other. In the test described above, the engineer tested a prototype of a bridge in high wind. Then, identify what the test measured. One of the criteria for the bridge was that it not move too much in high winds. The test measured how much the prototype bridge moved. Tests can show how well one or more designs meet the criteria. The test described above can show whether the bridge would move too much in high winds.
Which of these states is farthest north?
[ "West Virginia", "Tennessee", "Florida", "Louisiana" ]
0
closed choice
grade2
social science
geography
Geography
Read a map: cardinal directions
Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.
To find the answer, look at the compass rose. Look at which way the north arrow is pointing. West Virginia is farthest north.
Not supported with pagination yet
What is the mass of a news magazine?
[ "10 ounces", "10 pounds", "10 tons" ]
0
Select the best estimate.
closed choice
grade4
natural science
units-and-measurement
Units and measurement
Choose customary units of mass
Measurements are written with both a number and a unit. The unit comes after the number. The unit shows what the number means. Mass is a measurement of how much matter something contains. There are many different units of mass. When you are using customary units, mass may be written with units of ounces, pounds, or tons. There are 16 ounces in 1 pound and 2,000 pounds in 1 ton. So, 1 ounce is less than 1 pound and much less than 1 ton. A slice of bread has a mass of about 1 ounce, while a can of beans has a mass of about 1 pound. A small car has a mass of about 1 ton.
The best estimate for the mass of a news magazine is 10 ounces. 10 pounds and 10 tons are both too heavy.
Not supported with pagination yet
Which change better matches the sentence? Pieces of rock and soil are washed away by water.
[ "earthquake", "erosion" ]
1
closed choice
grade2
natural science
earth-science
Earth events
Classify changes to Earth's surface
Which of these continents does the prime meridian intersect?
[ "Africa", "Australia", "South America" ]
0
closed choice
grade4
social science
geography
Maps
Use lines of latitude and longitude
Lines of latitude and lines of longitude are imaginary lines drawn on some globes and maps. They can help you find places on globes and maps. Lines of latitude show how far north or south a place is. We use units called degrees to describe how far a place is from the equator. The equator is the line located at 0° latitude. We start counting degrees from there. Lines north of the equator are labeled N for north. Lines south of the equator are labeled S for south. Lines of latitude are also called parallels because each line is parallel to the equator. Lines of longitude are also called meridians. They show how far east or west a place is. We use degrees to help describe how far a place is from the prime meridian. The prime meridian is the line located at 0° longitude. Lines west of the prime meridian are labeled W. Lines east of the prime meridian are labeled E. Meridians meet at the north and south poles. The equator goes all the way around the earth, but the prime meridian is different. It only goes from the North Pole to the South Pole on one side of the earth. On the opposite side of the globe is another special meridian. It is labeled both 180°E and 180°W. Together, lines of latitude and lines of longitude form a grid. You can use this grid to find the exact location of a place.
The prime meridian is the line at 0° longitude. It intersects Africa. It does not intersect Australia or South America.
What is the capital of North Dakota?
[ "Little Rock", "Fargo", "Bismarck", "Grand Rapids" ]
2
closed choice
grade4
social science
geography
State capitals
Identify state capitals of the Midwest
Bismarck is the capital of North Dakota.
Not supported with pagination yet
Which figure of speech is used in this text? If you're going to become true dodgeballers, then you've got to learn the five d's of dodgeball: dodge, duck, dip, dive and dodge! —Dodgeball: A True Underdog Story
[ "metaphor", "alliteration" ]
1
closed choice
grade7
language science
figurative-language
Literary devices
Classify figures of speech
Figures of speech are words or phrases that use language in a nonliteral or unusual way. They can make writing more expressive. Alliteration is the repetition of sounds at the beginning of nearby words. What a lucky little lady you are! An allusion is a brief reference to something or someone well known, often from history or literature. "I'd better get home before I turn into a pumpkin!" Lila remarked. An idiom is an expression that cannot be understood literally. Its meaning must be learned. The assignment was a piece of cake. A simile uses like or as to compare two things that are not actually alike. The cat's fur was as dark as the night. A metaphor compares two things that are not actually alike without using like or as. The snow formed a blanket over the town. Onomatopoeia involves using a word that expresses a sound. The scrambled eggs hit the floor with a splat. Personification is giving human characteristics to nonhuman things. The trees danced in the wind. A pun involves using a word or phrase in a humorous way that suggests more than one meaning. A great new broom is sweeping the nation. Verbal irony involves saying one thing but implying something very different. People often use verbal irony when they are being sarcastic. Olivia seems thrilled that her car keeps breaking down. Each breakdown is as enjoyable as a punch to the face.
The text uses alliteration, the repetition of sounds at the beginning of nearby words. D's of dodgeball: dodge, duck, dip, dive and dodge repeats the d sound.
Not supported with pagination yet
What does the verbal irony in this text suggest? "This is the best day of my life," Mr. Mercado mumbled after his car broke down on the way to an important job interview.
[ "Mr. Mercado was already running late.", "Mr. Mercado was having a bad day." ]
1
closed choice
grade7
language science
figurative-language
Literary devices
Interpret figures of speech
Figures of speech are words or phrases that use language in a nonliteral or unusual way. They can make writing more expressive. Verbal irony involves saying one thing but implying something very different. People often use verbal irony when they are being sarcastic. Olivia seems thrilled that her car keeps breaking down. Each breakdown is as enjoyable as a punch to the face.
The text uses verbal irony, which involves saying one thing but implying something very different. The best day of my life ironically suggests that Mr. Mercado was having a bad day. He was having the opposite of a good day because his car broke down when he needed to be on time.
Which country is highlighted?
[ "Palau", "Tuvalu", "Nauru", "Kiribati" ]
3
closed choice
grade8
social science
geography
Oceania: geography
Identify and select countries of Oceania
This country is Kiribati.
Which country is highlighted?
[ "Cuba", "Jamaica", "Haiti", "Dominica" ]
1
closed choice
grade6
social science
geography
The Americas: geography
Identify and select countries of the Caribbean
This country is Jamaica.
In this food chain, the diatom is a producer. Why?
[ "It eats another organism.", "It makes its own food.", "It eats a consumer." ]
1
This diagram shows a food chain from the River Frome, a freshwater ecosystem in England.
closed choice
grade5
natural science
biology
Ecosystems
Identify roles in food chains
Every organism needs food to stay alive. Organisms get their food in different ways. A food chain shows how organisms in an ecosystem get their food. The food chain begins with the producer. A producer can change matter that is not food into food. Many producers use carbon dioxide, water, and sunlight to make sugar. Carbon dioxide and water are not food, but sugar is food for the producer. Consumers eat other organisms. There can be several kinds of consumers in a food chain: A primary consumer eats producers. The word primary tells you that this is the first consumer in a food chain. A secondary consumer eats primary consumers. The word secondary tells you that this is the second consumer in a food chain. A tertiary consumer eats secondary consumers. The word tertiary tells you that this is the third consumer in a food chain. A top consumer is the animal at the top of a food chain. Food chains can have different numbers of organisms. For example, when there are four organisms in the chain, the top consumer is the tertiary consumer. But if there are five organisms in the chain, the top consumer eats the tertiary consumer!
In this food chain, the diatom is a producer because it makes its own food. The diatom uses carbon dioxide, water, and sunlight to make its own food.
Not supported with pagination yet
Is there a surplus or a shortage of stuffed elephants?
[ "surplus", "shortage" ]
1
A toy store has 40 stuffed elephants for sale. The elephants cost $25 each. At that price, 60 people want to buy one.
closed choice
grade5
social science
economics
Supply and demand
Identify shortage and surplus
There is a surplus if there is too much for sale at a given price. There is a shortage if there is not enough for sale at a given price. Surpluses and shortages usually happen when people who are selling goods or services charge too much or too little. When the price is too high, consumers will not want to buy much of the good or service. The quantity demanded will be less than the quantity supplied. So, there will be a surplus. When the price is too low, too many consumers will want to buy the good or service. The quantity demanded will be more than the quantity supplied. So, there will be a shortage.
At the current price, there are not enough stuffed elephants for sale. There are 40 elephants for sale, but 60 people want to buy one. So, there is a shortage of stuffed elephants.
Which rhetorical appeal is primarily used in this ad?
[ "ethos (character)", "pathos (emotion)", "logos (reason)" ]
1
closed choice
grade12
language science
writing-strategies
Persuasive strategies
Identify appeals to ethos, pathos, and logos in advertisements
The purpose of an advertisement is to persuade people to do something. To accomplish this purpose, advertisements use three types of persuasive strategies, or appeals. Appeals to ethos, or character, show the writer or speaker as trustworthy, authoritative, or sharing important values with the audience. An ad that appeals to ethos might do one of the following: say that a brand has been trusted for many years include an endorsement from a respected organization, such as the American Dental Association feature a testimonial from a "real person" who shares the audience's values use an admired celebrity or athlete as a spokesperson Appeals to logos, or reason, use logic and verifiable evidence. An ad that appeals to logos might do one of the following: use graphs or charts to display information cite results of clinical trials or independently conducted studies explain the science behind a product or service emphasize that the product is a financially wise choice anticipate and refute potential counterclaims Appeals to pathos, or emotion, use feelings rather than facts to persuade the audience. An ad that appeals to pathos might do one of the following: trigger a fear, such as the fear of embarrassment appeal to a desire, such as the desire to appear attractive link the product to a positive feeling, such as adventure, love, or luxury
The ad appeals to pathos, or emotion, by drawing on the reader's desire to stand out.
Not supported with pagination yet
Would you find the word hickory on a dictionary page with the following guide words? head - hurry
[ "yes", "no" ]
0
yes or no
grade4
language science
reference-skills
Reference skills
Use guide words
Guide words appear on each page of a dictionary. They tell you the first word and last word on the page. The other words on the page come between the guide words in alphabetical order. To put words in alphabetical order, put them in order by their first letters. If the first letters are the same, look at the second letters. If the second letters are the same, look at the third letters, and so on. If one word is shorter, and there are no more letters to compare, then the shorter word comes first in alphabetical order. For example, be comes before bed.
Put the words in alphabetical order. Since hickory is between the guide words head - hurry, it would be found on that page.
Which better describes the Coral Triangle ecosystem?
[ "It has water with not much salt. It also has only a few types of organisms.", "It has many different types of organisms. It also has shallow water." ]
1
Figure: Coral Triangle. The Coral Triangle is a tropical coral reef ecosystem in the western Pacific Ocean.
closed choice
grade3
natural science
biology
Ecosystems
Describe ecosystems
An ecosystem is formed when living and nonliving things interact in an environment. There are many types of ecosystems. Here are some ways in which ecosystems can differ from each other: the pattern of weather, or climate the type of soil or water the organisms that live there
A tropical coral reef is a type of ecosystem. Tropical coral reefs have the following features: shallow, salty water, bright sunlight, and many different types of organisms. So, the Coral Triangle has many different types of organisms. It also has shallow water.
What is this trapdoor spider's scientific name?
[ "Aptostichus cabrillo", "Aptostichus stephencolberti" ]
1
This species of trapdoor spider lives in sand dunes on the coast of California. This species was discovered in 2007 and is named after the comedian Stephen Colbert.
closed choice
grade4
natural science
biology
Scientific names
Origins of scientific names
When a scientist identifies a new organism, he or she chooses its scientific name. Sometimes, an organism is named after the place where it was first found. Other times, an organism is named after the scientist who first identified it. Or, the scientific name might describe the organism's physical traits. Many of the words that make up scientific names are based on words from old languages, like Latin and classical Greek. Sometimes, English words are changed to make them sound more like Latin or Greek. The new words are then used in an organism's scientific name.
This organism's scientific name refers to Stephen Colbert. The word stephencolberti refers to Stephen Colbert. So, this trapdoor spider's scientific name is Aptostichus stephencolberti.
What is the capital of Utah?
[ "Provo", "Salt Lake City", "Indianapolis", "Salem" ]
1
closed choice
grade5
social science
geography
State capitals
Identify state capitals of the West
Salt Lake City is the capital of Utah.
Not supported with pagination yet
What information supports the conclusion that Santiago inherited this trait?
[ "Santiago wears glasses and so do his sisters.", "Santiago's friend also has hazel eyes.", "Santiago's biological father wears contacts in his hazel eyes." ]
2
Read the description of a trait. Santiago has hazel eyes.
closed choice
grade7
natural science
biology
Genes to traits
Inherited and acquired traits: use evidence to support a statement
Organisms, including people, have both inherited and acquired traits. Inherited and acquired traits are gained in different ways. Inherited traits are passed down from biological parents to their offspring through genes. Genes are pieces of hereditary material that contain the instructions that affect inherited traits. Offspring receive their genes, and therefore gain their inherited traits, from their biological parents. Inherited traits do not need to be learned. Acquired traits are gained during a person's life. Some acquired traits, such as riding a bicycle, are gained by learning. Other acquired traits, such as scars, are caused by the environment. Parents do not pass acquired traits down to their offspring.
Which part of a moss plant produces spores?
[ "the sperm", "thin brown stalks" ]
1
This diagram shows the life cycle of a moss.
closed choice
grade7
natural science
biology
Plant reproduction
Moss and fern life cycles
Moss plants reproduce using both asexual reproduction and sexual reproduction. Moss plants use their male and female parts for sexual reproduction. The male parts produce sperm. Moss live in damp environments, and moss sperm can travel through water to the female parts. The sperm fuse with eggs in the female part. This is called fertilization. Self-fertilization happens when a sperm from a moss plant fertilizes an egg from the same plant. Cross-fertilization happens when a sperm from one moss plant fertilizes an egg from a different moss plant. The fertilized egg grows into a thin brown stalk on top of the female part. Each stalk has a small spore capsule at the top. Moss plants use asexual reproduction to make small spores in the capsules. When the capsules open, the spores are released. When the spores land on the ground, they may germinate and grow into a new moss plant. This new moss plant can produce eggs and sperm and begin the moss life cycle again.
A moss plant's thin brown stalks produce spores. The spores are released from the capsule at the top of the stalks. Sperm fuses with eggs to form fertilized eggs. Sperm do not produce spores.
Which property do these four objects have in common?
[ "soft", "smooth", "shiny" ]
0
Select the best answer.
closed choice
grade5
natural science
physics
Materials
Compare properties of objects
An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.
Look at each object. For each object, decide if it has that property. A smooth object is not scratchy or rough. The stuffed dice are not smooth. A soft object changes shape when pressed or squeezed. All four objects are soft. A shiny object reflects a lot of light. You can usually see your reflection in a shiny object. The stuffed dice and the stuffed rabbit are not shiny. The property that all four objects have in common is soft.
Which property do these four objects have in common?
[ "salty", "sweet", "rough" ]
2
Select the best answer.
closed choice
grade5
natural science
physics
Materials
Compare properties of objects
An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.
Look at each object. For each object, decide if it has that property. A rough object feels scratchy when you touch it. All four objects are rough. Potato chips have a salty taste. The pineapple is not salty. Sugar has a sweet taste. The pineapple is sweet, but the rock are not. The property that all four objects have in common is rough.
What is the name of the colony shown?
[ "North Carolina", "Indiana", "Virginia", "West Virginia" ]
2
closed choice
grade8
social science
us-history
Colonial America
Identify the Thirteen Colonies
The colony is Virginia. The Virginia Colony included land that would later become part of the state of West Virginia. West Virginia was never its own colony.
Not supported with pagination yet
Which word would you find on a dictionary page with the following guide words? hail - hound
[ "hunger", "hind" ]
1
closed choice
grade7
language science
reference-skills
Reference skills
Use guide words
Guide words appear on each page of a dictionary. They tell you the first word and last word on the page. The other words on the page come between the guide words in alphabetical order. To put words in alphabetical order, put them in order by their first letters. If the first letters are the same, look at the second letters. If the second letters are the same, look at the third letters, and so on. If one word is shorter, and there are no more letters to compare, then the shorter word comes first in alphabetical order. For example, be comes before bed.
Put the words in alphabetical order. Since hind is between the guide words hail - hound, it would be found on that page.
Which of the following could Nolan's test show?
[ "how well the weather station would work when it was windy", "if the weather station would work when the temperature was 50°C" ]
1
People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design. The passage below describes how the engineering-design process was used to test a solution to a problem. Read the passage. Then answer the question below. Nolan was a mechanical engineer who was designing to record temperature, precipitation, and wind speed. The weather station would be used in a town where the highest recorded temperature was 40°C. Nolan wanted to make sure the weather station would work even in unusually warm weather. So, he set an indoor test chamber to 50°C with low moisture and no wind. He left the weather station in the chamber overnight. The next day, he checked to see if the weather station displayed accurate measurements after 24 hours at 50°C. Figure: a weather station.
closed choice
grade6
natural science
science-and-engineering-practices
Engineering practices
Evaluate tests of engineering-design solutions
People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design. How can you determine what a test can show? You need to figure out what was tested and what was measured. Imagine an engineer needs to design a bridge for a windy location. She wants to make sure the bridge will not move too much in high wind. So, she builds a smaller prototype, or model, of a bridge. Then, she exposes the prototype to high winds and measures how much the bridge moves. First, identify what was tested. A test can examine one design, or it may compare multiple prototypes to each other. In the test described above, the engineer tested a prototype of a bridge in high wind. Then, identify what the test measured. One of the criteria for the bridge was that it not move too much in high winds. The test measured how much the prototype bridge moved. Tests can show how well one or more designs meet the criteria. The test described above can show whether the bridge would move too much in high winds.
Not supported with pagination yet
What does the verbal irony in this text suggest? After a jog around the block, Katie collapsed on the couch and declared with a wheeze, "Well, I'm ready to run a marathon."
[ "Katie felt full of energy.", "Katie was out of shape." ]
1
closed choice
grade10
language science
figurative-language
Literary devices
Interpret figures of speech
Figures of speech are words or phrases that use language in a nonliteral or unusual way. They can make writing more expressive. Verbal irony involves saying one thing but implying something very different. People often use verbal irony when they are being sarcastic. Olivia seems thrilled that her car keeps breaking down. Each breakdown is as enjoyable as a punch to the face.
The text uses verbal irony, which involves saying one thing but implying something very different. Ready to run a marathon ironically suggests that Katie was out of shape. She was actually far from ready to run a marathon.
Not supported with pagination yet
What is the volume of a water balloon?
[ "600 milliliters", "600 liters" ]
0
Select the better estimate.
closed choice
grade4
natural science
units-and-measurement
Units and measurement
Choose metric units of volume
Measurements are written with both a number and a unit. The unit comes after the number. The unit shows what the number means. Volume is a measurement of how much space something takes up. There are many different units of volume. When you are using metric units, volume may be written in units of milliliters or liters. There are 1,000 milliliters in 1 liter. So, 1 milliliter is much less than 1 liter. A raindrop has a volume of about 20 milliliters, while a large soda bottle has a volume of 2 liters. The flask shown here measures volumes up to 500 milliliters.
The better estimate for the volume of a water balloon is 600 milliliters. 600 liters is too much.
Which ocean is highlighted?
[ "the Atlantic Ocean", "the Indian Ocean", "the Arctic Ocean", "the Southern Ocean" ]
0
closed choice
grade8
social science
geography
Physical Geography
Oceans and continents
Oceans are huge bodies of salt water. The world has five oceans. All of the oceans are connected, making one world ocean.
This is the Atlantic Ocean.
Based on the arrows, which of the following living things is a consumer?
[ "kelp", "plainfin midshipman" ]
1
Below is a food web from an ocean ecosystem. The ecosystem is in Monterey Bay, off the coast of California. A food web is a model that shows how the matter eaten by living things moves through an ecosystem. The arrows show how matter moves through the food web.
closed choice
grade3
natural science
biology
Ecosystems
Interpret food webs
A food web is a model. Models can make things in nature easier to understand. Models can be simpler than the things they represent. A food web is a model that shows where living things in an ecosystem get their food. If a food web showed every living thing in an ecosystem, the food web would be hard to understand. So, each food web shows how some living things in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one living thing to another. Each arrow shows the direction that matter moves when one living thing eats another living thing. An arrow starts from the living thing that is eaten. The arrow points to the living thing that is doing the eating. A living thing in a food web can have more than one arrow pointing from it. This shows that the living thing is eaten by more than one other living thing in the food web. A living thing in a food web can also have more than one arrow pointing to it. This shows that the living thing eats more than one other living thing in the food web.
Consumers eat other living things. So, there are arrows in a food web that point from other living things to consumers. The plainfin midshipman has arrows pointing to it from the phytoplankton and the zooplankton. So, the plainfin midshipman is a consumer. The kelp does not have any arrows pointing to it. So, the kelp is a producer, not a consumer.
Not supported with pagination yet
Which tense does the sentence use? Lily will print her name with care.
[ "past tense", "future tense", "present tense" ]
1
closed choice
grade2
language science
verbs
Verb tense
Is the sentence in the past, present, or future tense?
Present tense verbs tell you about something that is happening now. Most present-tense verbs are regular. They have no ending, or they end in -s or -es. Two verbs are irregular in the present tense, to be and to have. You must remember their forms. Past tense verbs tell you about something that has already happened. Most past-tense verbs are regular. They end in -ed. Some verbs are irregular in the past tense. You must remember their past-tense forms. Future tense verbs tell you about something that is going to happen. All future-tense verbs use the word will. Present | Past | Future walk, walks | walked | will walk go, goes | went | will go
The sentence is in future tense. You can tell because it uses will before the main verb, print. The verb tells you about something that is going to happen.
Not supported with pagination yet
Which logical fallacy is used in the text? You may be impressed by Senator Carter's work with low-income communities, but the fact remains that he graduated from an elite university. He couldn't possibly empathize with low-income constituents.
[ "guilt by association: a negative association intended to discredit someone or something", "appeal to nature: the assumption that natural things are always good", "straw man: a misrepresentation of an opponent's position that makes it easier to argue against" ]
0
closed choice
grade11
language science
writing-strategies
Developing and supporting arguments
Classify logical fallacies
A strong argument uses valid reasoning and logic in support of a claim. When an argument or claim introduces irrelevant information or misrepresents the issues at hand, it may be committing a logical fallacy. Logical fallacies can hurt a writer's credibility and can lead readers to draw false conclusions. A logical fallacy may present irrelevant information: Fallacy | Description ad hominem | an attack against the person making the argument, rather than the argument itself appeal to nature | an argument that assumes the natural choice is always the best choice bandwagon fallacy | an argument that assumes the popular choice is always the best choice circular reasoning | an argument that supports a claim with the claim itself guilt by association | an unfair negative association with another person or group that is intended to discredit someone or something A logical fallacy may misrepresent the issues at hand: Fallacy | Description false causation | the assumption that because two things happened together, one caused the other false dichotomy | an argument that presents only two choices when more options exist hasty generalization | a broad claim based on too few observations slippery slope fallacy | the false assumption that a small first step will necessarily lead to extreme consequences straw man | a misrepresentation of an opponent's position that makes it easier to argue against
The text argues that Senator Carter can't empathize with his low-income constituents because he went to an elite university. However, going to an elite university doesn't necessarily mean you're out of touch. This illustrates a type of logical fallacy known as guilt by association.
Which country is highlighted?
[ "Tuvalu", "Palau", "the Federated States of Micronesia", "Australia" ]
1
closed choice
grade8
social science
geography
Oceania: geography
Identify and select countries of Oceania
This country is Palau.
Which country is highlighted?
[ "Vanuatu", "Tonga", "Fiji", "Solomon Islands" ]
2
closed choice
grade6
social science
geography
Oceania: geography
Identify and select countries of Oceania
This country is Fiji.
Not supported with pagination yet
What is the mass of a vacuum cleaner?
[ "7 kilograms", "7 grams" ]
0
Select the better estimate.
closed choice
grade5
natural science
units-and-measurement
Units and measurement
Choose metric units of mass
Measurements are written with both a number and a unit. The unit comes after the number. The unit shows what the number means. Mass is a measurement of how much matter something contains. There are many different units of mass. When you are using metric units, mass may be written with units of grams or kilograms. There are 1,000 grams in 1 kilogram. So, 1 gram is much less than 1 kilogram. A paper clip has a mass of about 1 gram, while a textbook has a mass of about 1 kilogram.
The better estimate for the mass of a vacuum cleaner is 7 kilograms. 7 grams is too light.
Not supported with pagination yet
Which closing is correct for a letter?
[ "Best wishes,\nCarmen", "best wishes,\nCarmen" ]
0
closed choice
grade2
language science
capitalization
Capitalization
Greetings and closings of letters
A letter starts with a greeting and ends with a closing. For each one, capitalize the first word and end with a comma. You should also capitalize proper nouns, such as Aunt Sue. Dear Aunt Sue, I'm glad you could come to my party, and thank you for the birthday gift. I could not have asked for a better one! Every time I see it, I think of you. With love, Rory
The second closing is correct: Its first word is capitalized, and it ends with a comma.
Not supported with pagination yet
Last year, 50,000 people lived in the city of Westford. But since then, 8,000 people have moved away. What probably happened to the overall supply of houses for sale in Westford?
[ "The supply probably went up.", "The supply probably went down." ]
0
closed choice
grade6
social science
economics
Supply and demand
Understand overall supply and demand
Overall supply is the total amount of a good or service that producers make and sell. There are several things that can make overall supply go up or down. The table below shows how changes to these things might affect overall supply. | Resources | Number of producers or suppliers | Expected change in demand Supply goes up | when resources cost less or are easier to get | when there are more producers or suppliers | when demand is expected to go up Supply goes down | when resources cost more or are harder to get | when there are fewer producers or suppliers | when demand is expected to go down Producers are people or companies that make goods or provide services. Suppliers are people or companies that sell goods or services. New inventions or technologies can also help workers produce goods and services more quickly. As a result of these changes, the supply of a good or service will often go up.
The population of Westford fell by 8,000 people. Many of the people who have left are probably trying to sell their houses. Since more people are trying to sell their houses, the number of suppliers of houses for sale in Westford has gone up. So, the supply of houses for sale probably went up, too.
Not supported with pagination yet
Which figure of speech is used in this text? Reba, please stay away from the ocean. You shouldn't go in the water until you know how to swim.
[ "euphemism", "paradox" ]
1
closed choice
grade12
language science
figurative-language
Literary devices
Classify the figure of speech: euphemism, hyperbole, oxymoron, paradox
Figures of speech are words or phrases that use language in a nonliteral or unusual way. They can make writing more expressive. A euphemism is a polite or indirect expression that is used to de-emphasize an unpleasant topic. The head of Human Resources would never refer to firing people, only to laying them off. Hyperbole is an obvious exaggeration that is not meant to be taken literally. I ate so much that I think I might explode! An oxymoron is a joining of two seemingly contradictory terms. Some reviewers are calling this book a new classic. A paradox is a statement that might at first appear to be contradictory, but that may in fact contain some truth. Always expect the unexpected.
The text uses a paradox, a statement that might at first appear to be contradictory, but that may in fact contain some truth. You shouldn't go in the water until you know how to swim at first appears to be contradictory, because it is impossible to learn how to swim without going in the water. However, it contains some truth: you should not go into deep or dangerous water without first knowing how to swim.
What is the direction of this pull?
[ "toward the giraffe", "away from the giraffe" ]
0
A hungry giraffe pulls a leaf into her mouth.
closed choice
grade2
natural science
physics
Force and motion
Identify pushes and pulls
One object can make another object move with a push or a pull. The direction of a push is away from the object that is pushing. The direction of a pull is toward the object that is pulling.
The hungry giraffe pulls a leaf toward herself. She's ready to eat! The direction of the pull is toward the giraffe.
Not supported with pagination yet
Which change best matches the sentence? Water builds up in a city after heavy rain.
[ "flood", "wildfire", "earthquake" ]
0
closed choice
grade3
natural science
earth-science
Earth events
Classify changes to Earth's surface I
Not supported with pagination yet
Which logical fallacy is used in the text? Everyone I know is making fruit smoothies for quick, portable meals, so smoothies must be really good for you.
[ "hasty generalization: a very broad claim based on very little evidence", "bandwagon fallacy: the assumption that the popular choice is automatically correct" ]
1
closed choice
grade6
language science
writing-strategies
Developing and supporting arguments
Classify logical fallacies
A strong argument uses valid reasoning and logic in support of a claim. When an argument or claim introduces irrelevant information or misrepresents the issues at hand, it may be committing a logical fallacy. Logical fallacies can hurt a writer's credibility and can lead readers to draw false conclusions. A logical fallacy may present irrelevant information: Fallacy | Description ad hominem | a personal attack meant to discredit one's opponent appeal to nature | an argument that assumes the natural choice is always the best choice bandwagon fallacy | an argument that assumes the popular choice is always the best choice circular reasoning | an argument that supports a claim with the claim itself guilt by association | an unfair negative association with another person or group that is intended to discredit someone or something red herring | the use of a completely unrelated topic in support of a claim A logical fallacy may misrepresent the issues at hand: Fallacy | Description false causation | the assumption that because two things happened together, one caused the other false dichotomy | an argument that presents only two choices when more options exist hasty generalization | a very broad claim based on very little evidence straw man | a misrepresentation of an opponent's position that makes it easier to argue against
The text argues that fruit smoothies are good for you, because many people are drinking them. However, even though some people are drinking them, that doesn't necessarily mean that smoothies are necessarily healthful. This illustrates a type of logical fallacy known as the bandwagon fallacy.
Not supported with pagination yet
Based on this information, what is this plant's phenotype for the pod color trait?
[ "green pods", "yellow pods" ]
1
In a group of pea plants, some individuals have green pods and others have yellow pods. In this group, the gene for the pod color trait has two alleles. The allele for green pods (D) is dominant over the allele for yellow pods (d). A certain pea plant from this group has the homozygous genotype dd for the pod color gene.
closed choice
grade6
natural science
biology
Genes to traits
Genetics vocabulary: dominant and recessive
All organisms have pieces of hereditary material called genes, which are passed from parents to offspring. Genes contain instructions for building the parts of an organism. An organism's genes affect its observable traits, including its appearance, its behavior, and which diseases it may have. Genes may have different alleles, or forms, that can cause different versions of a trait. For example, flower color is a trait in pea plants. The gene for this trait has two possible alleles. Each allele is represented by an uppercase or lowercase letter. The allele F is for purple flowers, and the allele f is for white flowers. Each pea plant has two alleles for the flower color gene—one allele inherited from each parent. An organism's genotype for a gene is its combination of alleles for that gene. So, a pea plant may have a genotype of FF, Ff, or ff for the flower color gene. An organism's phenotype for a trait is its observable version of that trait, which depends on the organism's combination of alleles. A pea plant may have a phenotype of purple flowers or white flowers for the flower color trait. Some traits, like flower color in pea plants, are controlled by a single gene. Most plants and animals have a genotype made up of two alleles for these traits. These two alleles determine whether an organism is homozygous or heterozygous for the gene. An organism with two identical alleles for a gene is homozygous for that gene. A pea plant with the genotype FF or ff is homozygous for the flower color gene. An organism with two different alleles for a gene is heterozygous for that gene. A pea plant with the genotype Ff is heterozygous for the flower color gene. The types of alleles in an organism's genotype determine the organism's phenotype. Some alleles have types called dominant and recessive. These two types can cause different versions of a trait to appear as the organism's phenotype. A dominant allele causes its version of the trait to appear even when the organism also has a recessive allele for the gene. In pea plants, the F allele, which causes purple flowers, is dominant over the f allele. A pea plant with at least one F allele will have the F allele's version of the flower color trait. So, a plant with the genotype FF or Ff will have purple flowers. A recessive allele causes its version of the trait to appear only when the organism does not have any dominant alleles for the gene. In pea plants, the f allele, which causes white flowers, is recessive to the F allele. A pea plant with only f alleles will have the f allele's version of the flower color trait. So, a plant with the genotype ff will have white flowers.
The pea plant's genotype for the pod color gene is dd. The pea plant's genotype of dd has only d alleles. The d allele is for yellow pods. So, the pea plant's phenotype for the pod color trait must be yellow pods. To check this answer, consider whether the pea plant's alleles are dominant or recessive. The allele for green pods (D) is dominant over the allele for yellow pods (d). This means D is a dominant allele, and d is a recessive allele. The pea plant's genotype of dd has only recessive alleles. An organism with only recessive alleles for a gene will have the recessive allele's version of the trait. So, the pea plant's phenotype for the pod color trait must be yellow pods.
Which country is highlighted?
[ "Tuvalu", "the Federated States of Micronesia", "Palau", "Fiji" ]
2
closed choice
grade7
social science
geography
Oceania: geography
Identify and select countries of Oceania
This country is Palau.
What is the capital of Hawaii?
[ "Pierre", "Hilo", "Saint Louis", "Honolulu" ]
3
closed choice
grade3
social science
geography
State capitals
Identify the 50 state capitals
Honolulu is the capital of Hawaii.
What is the capital of New York?
[ "Carson City", "Albany", "Annapolis", "Augusta" ]
1
closed choice
grade4
social science
geography
State capitals
Identify state capitals of the Northeast
Albany is the capital of New York.
Not supported with pagination yet
Based on this information, what is this rainbow trout's phenotype for the body color trait?
[ "Bb", "a greenish-brown body" ]
1
In a group of rainbow trout, some individuals have a greenish-brown body and others have a blue body. In this group, the gene for the body color trait has two alleles. The allele B is for a greenish-brown body, and the allele b is for a blue body. A certain rainbow trout from this group has a greenish-brown body. This trout has one allele for a greenish-brown body and one allele for a blue body.
closed choice
grade8
natural science
biology
Genes to traits
Genetics vocabulary: genotype and phenotype
All organisms have pieces of hereditary material called genes, which are passed from parents to offspring. Genes contain instructions for building the parts of an organism. An organism's genes affect its observable traits, including its appearance, its behavior, and which diseases it may have. Genes may have different alleles, or forms, that can cause different versions of a trait. For example, flower color is a trait in pea plants. The gene for this trait has two possible alleles. Each allele is represented by an uppercase or lowercase letter. The allele F is for purple flowers, and the allele f is for white flowers. Each pea plant has two alleles for the flower color gene—one allele inherited from each parent. An organism's genotype for a gene is its combination of alleles for that gene. So, a pea plant may have a genotype of FF, Ff, or ff for the flower color gene. An organism's phenotype for a trait is its observable version of that trait, which depends on the organism's combination of alleles. A pea plant may have a phenotype of purple flowers or white flowers for the flower color trait.
An organism's phenotype for a trait is its observable version of that trait. The rainbow trout's observable version of the body color trait is a greenish-brown body. So, the trout's phenotype for the body color trait is a greenish-brown body.
Identify the question that Kenji's experiment can best answer.
[ "Do more bacteria grow in liquid with cinnamon than in liquid without cinnamon?", "Does temperature affect how much bacteria can grow in liquid?" ]
0
The passage below describes an experiment. Read the passage and then follow the instructions below. Kenji mixed bacteria into a nutrient-rich liquid where the bacteria could grow. He poured four ounces of the mixture into each of ten glass flasks. In five of the ten flasks, he also added one teaspoon of cinnamon. He allowed the bacteria in the flasks to grow overnight in a 37°C room. Then, Kenji used a microscope to count the number of bacteria in a small sample from each flask. He compared the amount of bacteria in the liquid with cinnamon to the amount of bacteria in the liquid without cinnamon. Figure: flasks of liquid for growing bacteria.
closed choice
grade8
natural science
science-and-engineering-practices
Designing experiments
Identify the experimental question
Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment. Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured. First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested. Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured. Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height. Examples of questions that this experiment can answer include: Does soil type affect the height of daffodil plants? Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil? Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?
Which better describes the Kibale National Forest ecosystem?
[ "It has year-round warm temperatures. It also has soil that is poor in nutrients.", "It has soil that is poor in nutrients. It also has only a few types of organisms." ]
0
Figure: Kibale National Forest. Kibale National Forest is a tropical rain forest ecosystem in Uganda, a country in eastern Africa.
closed choice
grade4
natural science
biology
Ecosystems
Describe ecosystems
An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment. There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other: the pattern of weather, or climate the type of soil the organisms that live there
A tropical rain forest is a type of ecosystem. Tropical rain forests have the following features: year-round rain and warm temperatures, soil that is poor in nutrients, and many different types of organisms. So, Kibale National Forest has year-round warm temperatures. It also has soil that is poor in nutrients.
Not supported with pagination yet
What information supports the conclusion that Henry acquired this trait?
[ "Henry won a competition at his school with his jump rope tricks.", "Henry's sister taught him how to do tricks with a jump rope.", "Henry has three jump ropes, each made of a different material." ]
1
Read the description of a trait. Henry knows how to do tricks with a jump rope.
closed choice
grade7
natural science
biology
Genes to traits
Inherited and acquired traits: use evidence to support a statement
Organisms, including people, have both inherited and acquired traits. Inherited and acquired traits are gained in different ways. Inherited traits are passed down from biological parents to their offspring through genes. Genes are pieces of hereditary material that contain the instructions that affect inherited traits. Offspring receive their genes, and therefore gain their inherited traits, from their biological parents. Inherited traits do not need to be learned. Acquired traits are gained during a person's life. Some acquired traits, such as riding a bicycle, are gained by learning. Other acquired traits, such as scars, are caused by the environment. Parents do not pass acquired traits down to their offspring.
What is the name of the colony shown?
[ "New York", "Vermont", "Michigan", "Indiana" ]
0
closed choice
grade5
social science
us-history
English colonies in North America
Identify the Thirteen Colonies
The colony is New York. During the colonial era, New Hampshire and New York both claimed the territory that would later become the state of Vermont. Vermont was never its own colony.
Not supported with pagination yet
The city of Lexington has been one of the world's biggest makers of cough drops for many years. But last month, Lexington's cough drop factories were destroyed by floods. What will probably happen to the overall supply of cough drops?
[ "The supply will probably go up.", "The supply will probably go down." ]
1
closed choice
grade6
social science
economics
Supply and demand
Understand overall supply and demand
Overall supply is the total amount of a good or service that producers make and sell. There are several things that can make overall supply go up or down. The table below shows how changes to these things might affect overall supply. | Resources | Number of producers or suppliers | Expected change in demand Supply goes up | when resources cost less or are easier to get | when there are more producers or suppliers | when demand is expected to go up Supply goes down | when resources cost more or are harder to get | when there are fewer producers or suppliers | when demand is expected to go down Producers are people or companies that make goods or provide services. Suppliers are people or companies that sell goods or services. New inventions or technologies can also help workers produce goods and services more quickly. As a result of these changes, the supply of a good or service will often go up.
Floods destroyed the cough drop factories in Lexington. The number of producers of cough drops went down. So, the supply of cough drops will probably go down.
Think about the magnetic force between the magnets in each pair. Which of the following statements is true?
[ "The magnetic force is weaker in Pair 1.", "The strength of the magnetic force is the same in both pairs.", "The magnetic force is weaker in Pair 2." ]
2
The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material.
closed choice
grade3
natural science
physics
Magnets
Compare strengths of magnetic forces
Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The stronger the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the strength of a magnetic force between two magnets by changing the distance between them. The magnetic force is weaker when the magnets are farther apart.
Distance affects the strength of the magnetic force. When magnets are farther apart, the magnetic force between them is weaker. The magnets in Pair 2 are farther apart than the magnets in Pair 1. So, the magnetic force is weaker in Pair 2 than in Pair 1.
Not supported with pagination yet
Compare the motion of two humpback whales. Which humpback whale was moving at a lower speed?
[ "a humpback whale that moved 60kilometers in 10hours", "a humpback whale that moved 30kilometers in 10hours" ]
1
closed choice
grade2
natural science
physics
Force and motion
Compare the speeds of moving objects
An object's speed tells you how fast the object is moving. Speed depends on both distance and time. Distance tells you how far the object has moved. One unit used to measure distance is the kilometer. Time tells you how long the object has spent moving. One unit used to measure time is the hour. Think about two objects moving for the same amount of time. The object that is moving slower will go a shorter distance in that time. It is moving at a lower speed.
Look at the distance each humpback whale moved and the time it took to move that distance. One humpback whale moved 30 kilometers in 10 hours. The other humpback whale moved 60 kilometers in 10 hours. Notice that each humpback whale spent the same amount of time moving. The humpback whale that moved 30 kilometers moved a shorter distance in that time. So, that humpback whale must have moved at a lower speed.
Think about the magnetic force between the magnets in each pair. Which of the following statements is true?
[ "The magnitude of the magnetic force is smaller in Pair 2.", "The magnitude of the magnetic force is the same in both pairs.", "The magnitude of the magnetic force is smaller in Pair 1." ]
0
The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different shapes.
closed choice
grade5
natural science
physics
Magnets
Compare magnitudes of magnetic forces
Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is smaller when there is a greater distance between the magnets.
The magnets in Pair 1 attract. The magnets in Pair 2 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force. Distance affects the magnitude of the magnetic force. When there is a greater distance between magnets, the magnitude of the magnetic force between them is smaller. There is a greater distance between the magnets in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is smaller in Pair 2 than in Pair 1.
Think about the magnetic force between the magnets in each pair. Which of the following statements is true?
[ "The magnitude of the magnetic force is smaller in Pair 2.", "The magnitude of the magnetic force is the same in both pairs.", "The magnitude of the magnetic force is smaller in Pair 1." ]
0
The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material.
closed choice
grade7
natural science
physics
Velocity, acceleration, and forces
Compare magnitudes of magnetic forces
Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is smaller when there is a greater distance between the magnets.
The magnets in Pair 1 attract. The magnets in Pair 2 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force. Distance affects the magnitude of the magnetic force. When there is a greater distance between magnets, the magnitude of the magnetic force between them is smaller. There is a greater distance between the magnets in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is smaller in Pair 2 than in Pair 1.
What is the capital of Colorado?
[ "Denver", "Salem", "Olympia", "Charleston" ]
0
closed choice
grade4
social science
geography
State capitals
Identify the 50 state capitals
Denver is the capital of Colorado.
What does pollen help a plant do?
[ "grow bigger", "make seeds", "grow new leaves" ]
1
The male part of a flower makes pollen.
closed choice
grade4
natural science
biology
Plants
Describe and construct flowering plant life cycles
Many plants have flowers. These plants can use their flowers to reproduce, or make new plants like themselves. How do plants use their flowers to reproduce? First, the male part of the flower makes pollen, and the female part makes eggs. Animals, wind, or water can move pollen. Pollination is what happens when pollen is moved to the female part of the flower. After pollination, sperm from the pollen can combine with the eggs. This is called fertilization. The fertilized eggs grow into seeds. The fruit grows around the seeds. Later, a seed can fall out of the fruit. It can germinate, or start to grow into a new plant.
Pollen helps the flower make seeds. After pollination, sperm cells from the pollen can combine with the eggs. These fertilized eggs can grow into seeds. Pollen does not help a plant grow bigger or grow leaves.
Which solution has a higher concentration of blue particles?
[ "neither; their concentrations are the same", "Solution A", "Solution B" ]
2
The diagram below is a model of two solutions. Each blue ball represents one particle of solute.
closed choice
grade7
natural science
chemistry
Solutions
Compare concentrations of solutions
A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent
In Solution A and Solution B, the blue particles represent the solute. To figure out which solution has a higher concentration of blue particles, look at both the number of blue particles and the volume of the solvent in each container. Use the concentration formula to find the number of blue particles per milliliter. Solution B has more blue particles per milliliter. So, Solution B has a higher concentration of blue particles.
Not supported with pagination yet
Which logical fallacy is used in the text? Mayor Goodman wants to create more bicycle lanes in Milford. However, many citizens of Milford live far from work. It would not be realistic to force us to give up our cars and bike everywhere.
[ "bandwagon fallacy: the assumption that the popular choice is automatically correct", "circular reasoning: an argument that supports a claim with the claim itself", "straw man: a misrepresentation of an opponent's position that makes it easier to argue against" ]
2
closed choice
grade12
language science
writing-strategies
Developing and supporting arguments
Classify logical fallacies
A strong argument uses valid reasoning and logic in support of a claim. When an argument or claim introduces irrelevant information or misrepresents the issues at hand, it may be committing a logical fallacy. Logical fallacies can hurt a writer's credibility and can lead readers to draw false conclusions. A logical fallacy may present irrelevant information: Fallacy | Description ad hominem | an attack against the person making the argument, rather than the argument itself appeal to nature | an argument that assumes the natural choice is always the best choice bandwagon fallacy | an argument that assumes the popular choice is always the best choice circular reasoning | an argument that supports a claim with the claim itself guilt by association | an unfair negative association with another person or group that is intended to discredit someone or something A logical fallacy may misrepresent the issues at hand: Fallacy | Description false causation | the assumption that because two things happened together, one caused the other false dichotomy | an argument that presents only two choices when more options exist hasty generalization | a broad claim based on too few observations slippery slope fallacy | the false assumption that a small first step will necessarily lead to extreme consequences straw man | a misrepresentation of an opponent's position that makes it easier to argue against
The text argues that Mayor Goodman wants people to give up their cars. However, this misrepresents Mayor Goodman's argument. Mayor Goodman only wants to create more bike lanes. This illustrates a type of logical fallacy known as a straw man.
Look at the models of molecules below. Select the elementary substance.
[ "fluoromethanol", "bromine", "cyclopropane" ]
1
closed choice
grade6
natural science
chemistry
Atoms and molecules
Identify elementary substances and compounds using models
There are more than 100 different chemical elements, or types of atoms. Chemical elements make up all of the substances around you. A substance may be composed of one chemical element or multiple chemical elements. Substances that are composed of only one chemical element are elementary substances. Substances that are composed of multiple chemical elements bonded together are compounds. Every chemical element is represented by its own atomic symbol. An atomic symbol may consist of one capital letter, or it may consist of a capital letter followed by a lowercase letter. For example, the atomic symbol for the chemical element boron is B, and the atomic symbol for the chemical element chlorine is Cl. Scientists use different types of models to represent substances whose atoms are bonded in different ways. One type of model is a ball-and-stick model. The ball-and-stick model below represents a molecule of the compound boron trichloride. In a ball-and-stick model, the balls represent atoms, and the sticks represent bonds. Notice that the balls in the model above are not all the same color. Each color represents a different chemical element. The legend shows the color and the atomic symbol for each chemical element in the substance.
Not supported with pagination yet
Which text uses the word disinterested in its traditional sense?
[ "Myra is happy with her position as class treasurer. Though she would have the support of the student council, she is disinterested in running for student body president.", "Myra is excellent in her position as class treasurer. She always manages to be disinterested in student council debates about the allocation of extracurricular funds." ]
1
closed choice
grade12
language science
writing-strategies
Word usage and nuance
Explore words with new or contested usages
Words change in meaning when speakers begin using them in new ways. For example, the word peruse once only meant to examine in detail, but it's now also commonly used to mean to look through in a casual manner. When a word changes in meaning, its correct usage is often debated. Although a newer sense of the word may be more commonly used, many people consider a word's traditional definition to be the correct usage. Being able to distinguish the different uses of a word can help you use it appropriately for different audiences. Britney perused her notes, carefully preparing for her exam. The traditional usage above is considered more standard. David perused the magazine, absentmindedly flipping through the pages. The nontraditional usage above is now commonly used, but traditional style guides generally advise against it.
The first text uses disinterested in its traditional sense: unbiased or impartial. Myra is excellent in her position as class treasurer. She always manages to be disinterested in student council debates about the allocation of extracurricular funds. The second text uses disinterested in its nontraditional sense: uninterested or indifferent. Myra is happy with her position as class treasurer. Though she would have the support of the student council, she is disinterested in running for student body president. Most style guides recommend to use the traditional sense of the word disinterested because it is considered more standard.
What is the capital of Delaware?
[ "Trenton", "Raleigh", "Wilmington", "Dover" ]
3
closed choice
grade5
social science
geography
State capitals
Identify state capitals of the Northeast
Dover is the capital of Delaware.
Which trait did Stenophlebia have? Select the trait you can observe on the fossil.
[ "a long, thin body", "thin legs" ]
0
This picture shows a fossil of an ancient insect called Stenophlebia. Fossils of Stenophlebia have been found in rocks that are more than 140,000,000 years old.
closed choice
grade3
natural science
earth-science
Fossils
Compare fossils to modern organisms
The way an organism looks or acts is called a trait. Scientists use fossils to learn more about the traits of ancient organisms. Fossils can preserve the remains of body parts and activities. A fossil of a body part, such as a tail or a wing, can tell you what an organism looked like. A fossil of an organism's activities, such as a burrow or a footprint, can tell you about the organism's behavior. Here are three examples of fossils and the traits that you can observe from them: This is a fossil of an animal. This fossil tells you that the animal had a spiral-shaped shell. This is a fossil of a plant. This fossil tells you that the plant had small leaves arranged in a branched pattern. This is a fossil of an animal's footprint. This fossil tells you that the animal could walk on land. An organism's fossil may not show all of the organism's traits. This is because most body parts are destroyed during fossil formation. When an organism's body turns into a fossil, only a few body parts are usually preserved.
What is the capital of Rhode Island?
[ "Providence", "Albany", "Newport", "Augusta" ]
0
closed choice
grade3
social science
geography
State capitals
Identify state capitals of the Northeast
Providence is the capital of Rhode Island.
Not supported with pagination yet
Which word would you find on a dictionary page with the following guide words? thin - trouble
[ "tug", "to" ]
1
closed choice
grade8
language science
reference-skills
Reference skills
Use guide words
Guide words appear on each page of a dictionary. They tell you the first word and last word on the page. The other words on the page come between the guide words in alphabetical order. To put words in alphabetical order, put them in order by their first letters. If the first letters are the same, look at the second letters. If the second letters are the same, look at the third letters, and so on. If one word is shorter, and there are no more letters to compare, then the shorter word comes first in alphabetical order. For example, be comes before bed.
Put the words in alphabetical order. Since to is between the guide words thin - trouble, it would be found on that page.
Not supported with pagination yet
Would you find the word album on a dictionary page with the following guide words? ache - anxiety
[ "yes", "no" ]
0
yes or no
grade7
language science
reference-skills
Reference skills
Use guide words
Guide words appear on each page of a dictionary. They tell you the first word and last word on the page. The other words on the page come between the guide words in alphabetical order. To put words in alphabetical order, put them in order by their first letters. If the first letters are the same, look at the second letters. If the second letters are the same, look at the third letters, and so on. If one word is shorter, and there are no more letters to compare, then the shorter word comes first in alphabetical order. For example, be comes before bed.
Put the words in alphabetical order. Since album is between the guide words ache - anxiety, it would be found on that page.
Not supported with pagination yet
Select the plant.
[ "Cypress trees have green leaves.", "Lionfish swim underwater." ]
0
closed choice
grade2
natural science
biology
Classification
Identify plants and animals
Plants and animals are living things. Living things are called organisms. Plants come in many shapes and sizes. Most plants grow in the ground. They might grow leaves, flowers, and fruit. Plants cannot move around on their own like animals can. Animals also come in many shapes and sizes. Most animals can move around. Animals might run, swim, jump, or fly. Animals eat plants or other organisms for food.
A lionfish is an animal. It swims underwater. Lionfish have poisonous venom on the tips of their fins. This poison helps protect lionfish from predators. A cypress tree is a plant. It has green leaves. The leaves of cypress trees are called needles.
Not supported with pagination yet
What do these two changes have in common? compost rotting cooking a pancake
[ "Both are caused by heating.", "Both are only physical changes.", "Both are chemical changes.", "Both are caused by cooling." ]
2
closed choice
grade3
natural science
chemistry
Physical and chemical change
Compare physical and chemical changes
Chemical changes and physical changes are two common ways matter can change. In a chemical change, the type of matter changes. The types of matter before and after a chemical change are always different. Some chemical changes are caused by heating or cooling. For example, burning a piece of paper is a chemical change caused by heating. When paper gets hot enough, it re­acts with oxygen in the air and burns. The paper and oxygen change into ash and smoke. In a physical change, the type of matter stays the same. The types of matter before and after a physical change are always the same. A change of state is a type of physical change. Changes of state can be caused by heating or cooling. For example, ice melting is a physical change that can be caused by heating. Ice and liquid water are made of the same type of matter: water. The law of conservation of mass says that all physical and chemical changes conserve mass. Conserve means to keep the same. So, the total mass before a physical or chemical change is equal to the total mass after the change.
Step 1: Think about each change. Compost forms from the remains of plants and animals, such as vegetable scraps and egg shells. Compost rotting is a chemical change. As the compost rots, it breaks down and turns into a different type of matter. Cooking a pancake is a chemical change. Pancakes are made from pancake batter. A cooked pancake is a different type of matter than pancake batter. Pancake batter is wet and slippery. Cooked pancakes are fluffy and can be good to eat! Step 2: Look at each answer choice. Both are only physical changes. Both changes are chemical changes. They are not physical changes. Both are chemical changes. Both changes are chemical changes. The type of matter before and after each change is different. Both are caused by heating. Cooking is caused by heating. But compost rotting is not. Both are caused by cooling. Neither change is caused by cooling.
Not supported with pagination yet
Complete the sentence. In this chemical reaction, gasoline is a ().
[ "reactant", "product" ]
0
This passage describes a chemical reaction. Read the passage. Then, follow the instructions below. Gasoline provides the energy that powers many car engines. In an engine, gasoline and oxygen are mixed together and burned, creating carbon dioxide gas and water vapor. This process releases energy that the engine uses to turn the wheels, making the car move.
closed choice
grade7
natural science
chemistry
Chemical reactions
Identify reactants and products
A chemical change occurs when new substances are formed from existing substances. This process is called a chemical reaction. In a chemical reaction, one or more substances change into one or more different substances. During the reaction, the atoms of the original substances are rearranged to form other substances. The original substances in a chemical reaction are called reactants. These substances react, or go through a chemical change. The substances that are formed in a chemical reaction are called products. These substances are produced by the chemical reaction. So, in a chemical reaction, reactants go through a chemical change to form products.
Read the underlined text carefully. Look for information about what happens to gasoline in this chemical reaction. Gasoline provides the energy that powers many car engines. In an engine, gasoline and oxygen are mixed together and burned, creating carbon dioxide gas and water vapor. This process releases energy that the engine uses to turn the wheels, making the car move. The underlined text tells you that when gasoline and oxygen combine, carbon dioxide and water are formed. When gasoline and oxygen react, or go through a chemical change, their atoms are rearranged to form carbon dioxide and water. Because gasoline reacts in this chemical reaction, gasoline is a reactant.
Not supported with pagination yet
Which tense does the sentence use? The clown jumps through the ring.
[ "future tense", "present tense", "past tense" ]
1
closed choice
grade2
language science
verbs
Verb tense
Is the sentence in the past, present, or future tense?
Present tense verbs tell you about something that is happening now. Most present-tense verbs are regular. They have no ending, or they end in -s or -es. Two verbs are irregular in the present tense, to be and to have. You must remember their forms. Past tense verbs tell you about something that has already happened. Most past-tense verbs are regular. They end in -ed. Some verbs are irregular in the past tense. You must remember their past-tense forms. Future tense verbs tell you about something that is going to happen. All future-tense verbs use the word will. Present | Past | Future walk, walks | walked | will walk go, goes | went | will go
The sentence is in present tense. You can tell because it uses a present-tense verb, jumps. The verb ends in -s and tells you about something that is true or happening now.
What is the name of the colony shown?
[ "Georgia", "Alabama", "Virginia", "Michigan" ]
0
closed choice
grade7
social science
us-history
Colonial America
Identify the Thirteen Colonies
The colony is Georgia.
Which material is this sandwich bag made of?
[ "plastic", "cotton" ]
0
closed choice
grade2
natural science
physics
Materials
Identify materials in objects
A material is a type of matter. Wood, glass, metal, and plastic are common materials.
Look at the picture of the sandwich bag. The bag is made of plastic.
Not supported with pagination yet
What kind of sentence is this? Never reveal the four-digit PIN that you use to make ATM transactions.
[ "exclamatory", "interrogative", "imperative" ]
2
closed choice
grade9
language science
punctuation
Sentences, fragments, and run-ons
Is the sentence declarative, interrogative, imperative, or exclamatory?
There are four kinds of sentences. A declarative sentence is a statement and always ends with a period. The nurse told Mr. Abrams to roll up his sleeve so that she could check his blood pressure. An imperative sentence makes a request or a demand and usually ends with a period. If a demand shows strong feeling, it can end with an exclamation point. For this assignment, use references to support your claims. Don't drive so quickly in the construction zone! An interrogative sentence asks a question and always ends with a question mark. Given the recent critiques of her new strategic plan, do you think the CEO will reconsider the company's direction? An exclamatory sentence is a statement that shows surprise or strong feeling. An exclamation always ends with an exclamation point. I can't wait to travel through Europe this summer!
The sentence makes a demand, so it is an imperative sentence. Here, it ends with a period.
Not supported with pagination yet
What information supports the conclusion that Caden inherited this trait?
[ "Caden's mother has blue eyes. She passed this trait down to Caden.", "Caden likes to wear a blue sweater to match his blue eyes." ]
0
Read the description of a trait. Caden has blue eyes.
closed choice
grade6
natural science
biology
Genes to traits
Inherited and acquired traits: use evidence to support a statement
Organisms, including people, have both inherited and acquired traits. Inherited and acquired traits are gained in different ways. Inherited traits are passed down from biological parents to their offspring through genes. Genes are pieces of hereditary material that contain the instructions that affect inherited traits. Offspring receive their genes, and therefore gain their inherited traits, from their biological parents. Inherited traits do not need to be learned. Acquired traits are gained during a person's life. Some acquired traits, such as riding a bicycle, are gained by learning. Other acquired traits, such as scars, are caused by the environment. Parents do not pass acquired traits down to their offspring.
Not supported with pagination yet
Which greeting is correct for a letter?
[ "Dear uncle scott,", "Dear Uncle Scott," ]
1
closed choice
grade2
language science
capitalization
Capitalization
Greetings and closings of letters
A letter starts with a greeting and ends with a closing. For each one, capitalize the first word and end with a comma. You should also capitalize proper nouns, such as Aunt Sue. Dear Aunt Sue, I'm glad you could come to my party, and thank you for the birthday gift. I could not have asked for a better one! Every time I see it, I think of you. With love, Rory
The first greeting is correct: Its first word is capitalized, and it ends with a comma. Uncle Scott is capitalized because it is a proper noun.
Which area voted for Lincoln?
[ "the Northeast", "the South" ]
0
In the 1860 election, the Republican party nominated Abraham Lincoln for president. Meanwhile, the Democrats could not decide on one candidate. Look at the 1860 election map. Then answer the question below.
closed choice
grade4
social science
us-history
The Civil War and Reconstruction
The Civil War: the beginning of the war
Not supported with pagination yet
Which change better matches the sentence? The trees in a forest catch fire and burn.
[ "volcanic eruption", "wildfire" ]
1
closed choice
grade2
natural science
earth-science
Earth events
Classify changes to Earth's surface
Which solution has a higher concentration of purple particles?
[ "Solution B", "neither; their concentrations are the same", "Solution A" ]
0
The diagram below is a model of two solutions. Each purple ball represents one particle of solute.
closed choice
grade7
natural science
chemistry
Solutions
Compare concentrations of solutions
A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent
In Solution A and Solution B, the purple particles represent the solute. To figure out which solution has a higher concentration of purple particles, look at both the number of purple particles and the volume of the solvent in each container. Use the concentration formula to find the number of purple particles per milliliter. Solution B has more purple particles per milliliter. So, Solution B has a higher concentration of purple particles.
Not supported with pagination yet
What do these two changes have in common? carving a piece of wood ice melting in a cup
[ "Both are caused by heating.", "Both are caused by cooling.", "Both are only physical changes.", "Both are chemical changes." ]
2
closed choice
grade8
natural science
chemistry
Chemical reactions
Compare physical and chemical changes
Matter is made of very small particles called atoms. Atoms can be linked together by chemical bonds. When two or more atoms link together, they form a molecule. In a chemical change, the chemical bonds in the molecules break. The atoms then link together to form different molecules. The types of molecules in matter before and after a chemical change are always different. Some chemical changes are caused by heating or cooling. For example, burning a piece of paper is a chemical change caused by heating. As paper burns, paper molecules react with oxygen molecules in the air. This reaction breaks the chemical bonds in the molecules. The atoms then link together in a different way to form different molecules. For example, carbon dioxide molecules are formed when paper burns. In a physical change, chemical bonds do not break. The types of molecules in matter before and after a physical change are always the same. A change of state is a type of physical change. Changes of state can be caused by heating or cooling. For example, water vaporizing is a physical change that can be caused by heating. Liquid water and water vapor are made of the same type of matter: water. The law of conservation of mass says that all physical and chemical changes conserve mass. Conserve means to keep the same. So, the total mass before a physical or chemical change is equal to the total mass after the change.
Step 1: Think about each change. Carving a piece of wood is a physical change. The wood changes shape, but it is still made of the same type of matter. Ice melting in a cup is a change of state. So, it is a physical change. The solid ice becomes liquid, but it is still made of water. The links between atoms in the water molecules do not change. So, a different type of matter is not formed. Step 2: Look at each answer choice. Both are only physical changes. Both changes are physical changes. No new matter is created. Both are chemical changes. Both changes are physical changes. They are not chemical changes. Both are caused by heating. Ice melting is caused by heating. But carving a piece of wood is not. Both are caused by cooling. Neither change is caused by cooling.
Not supported with pagination yet
Which logical fallacy is used in the text? My dentist recommends this toothpaste brand, but I'm reluctant to take the advice of someone with such bad taste. He has truly ugly art on the office walls, and the upholstery in his waiting room is atrocious.
[ "hasty generalization: a broad claim based on too few observations", "appeal to nature: the assumption that natural things are always good", "ad hominem: an attack against the person making the argument, rather than the argument itself" ]
2
closed choice
grade12
language science
writing-strategies
Developing and supporting arguments
Classify logical fallacies
A strong argument uses valid reasoning and logic in support of a claim. When an argument or claim introduces irrelevant information or misrepresents the issues at hand, it may be committing a logical fallacy. Logical fallacies can hurt a writer's credibility and can lead readers to draw false conclusions. A logical fallacy may present irrelevant information: Fallacy | Description ad hominem | an attack against the person making the argument, rather than the argument itself appeal to nature | an argument that assumes the natural choice is always the best choice bandwagon fallacy | an argument that assumes the popular choice is always the best choice circular reasoning | an argument that supports a claim with the claim itself guilt by association | an unfair negative association with another person or group that is intended to discredit someone or something A logical fallacy may misrepresent the issues at hand: Fallacy | Description false causation | the assumption that because two things happened together, one caused the other false dichotomy | an argument that presents only two choices when more options exist hasty generalization | a broad claim based on too few observations slippery slope fallacy | the false assumption that a small first step will necessarily lead to extreme consequences straw man | a misrepresentation of an opponent's position that makes it easier to argue against
The text argues that the dentist's professional recommendation is questionable because of his taste in art and furniture. This is a personal attack on the dentist that isn't relevant to whether his professional advice is valid. This illustrates a type of logical fallacy known as ad hominem.
Not supported with pagination yet
Which of the following contains a vague pronoun reference?
[ "The nurse examined the patient as soon as she arrived.", "The nurse examined the patient as soon as the patient arrived." ]
0
closed choice
grade7
language science
writing-strategies
Pronouns and antecedents
Identify vague pronoun references
When writing, make sure to avoid vague pronoun references. A vague pronoun reference occurs when a pronoun could refer to more than one possible antecedent. When Lisa and Kim finally landed, she breathed a sigh of relief. The pronoun she could refer to either Lisa or Kim, so the meaning of the sentence is unclear. Vague pronoun references can be corrected in one of two ways: 1. Replace the pronoun with its correct antecedent: When Lisa and Kim finally landed, Lisa breathed a sigh of relief. 2. Rewrite the sentence: Lisa breathed a sigh of relief when she and Kim finally landed. A vague pronoun reference also occurs when they, them, their, theirs, it, or its is used without its antecedent. They say that this nail polish dries in less than five minutes. The pronoun they is used without its antecedent, so the meaning of the sentence is unclear. This problem can be fixed by replacing the pronoun with its missing antecedent. The advertisements say that this nail polish dries in less than five minutes.
The second answer choice contains a vague pronoun reference. The pronoun she could refer to the nurse or the patient. The first answer choice shows a possible correction for the vague pronoun reference. She has been replaced with the patient. The nurse examined the patient as soon as the patient arrived.
Not supported with pagination yet
Which closing is correct for a letter?
[ "sincerely,\nHarry", "Sincerely,\nHarry" ]
1
closed choice
grade2
language science
capitalization
Capitalization
Greetings and closings of letters
A letter starts with a greeting and ends with a closing. For each one, capitalize the first word and end with a comma. You should also capitalize proper nouns, such as Aunt Sue. Dear Aunt Sue, I'm glad you could come to my party, and thank you for the birthday gift. I could not have asked for a better one! Every time I see it, I think of you. With love, Rory
The first closing is correct: Its first word is capitalized, and it ends with a comma.
Not supported with pagination yet
What kind of sentence is this? Evan campaigned tirelessly in support of his neighbor's bid for elective office.
[ "declarative", "interrogative", "exclamatory" ]
0
closed choice
grade9
language science
punctuation
Sentences, fragments, and run-ons
Is the sentence declarative, interrogative, imperative, or exclamatory?
There are four kinds of sentences. A declarative sentence is a statement and always ends with a period. The nurse told Mr. Abrams to roll up his sleeve so that she could check his blood pressure. An imperative sentence makes a request or a demand and usually ends with a period. If a demand shows strong feeling, it can end with an exclamation point. For this assignment, use references to support your claims. Don't drive so quickly in the construction zone! An interrogative sentence asks a question and always ends with a question mark. Given the recent critiques of her new strategic plan, do you think the CEO will reconsider the company's direction? An exclamatory sentence is a statement that shows surprise or strong feeling. An exclamation always ends with an exclamation point. I can't wait to travel through Europe this summer!
The sentence is a statement and ends with a period. It is a declarative sentence.
Not supported with pagination yet
Is a toaster a good or a service?
[ "a service", "a good" ]
1
closed choice
grade3
social science
economics
Basic economic principles
Goods and services
Everything you can buy is either a good or a service. A good is something you can touch or hold in your hands. For example, a hammer is a good. A service is a job you pay someone else to do. For example, cooking food in a restaurant is a service.
To decide whether a toaster is a good or a service, ask these questions: Is a toaster something you can touch? Yes. Is a toaster a job you might pay someone else to do? No. So, a toaster is a good.
Which solution has a higher concentration of yellow particles?
[ "Solution B", "Solution A", "neither; their concentrations are the same" ]
1
The diagram below is a model of two solutions. Each yellow ball represents one particle of solute.
closed choice
grade7
natural science
chemistry
Solutions
Compare concentrations of solutions
A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent
In Solution A and Solution B, the yellow particles represent the solute. To figure out which solution has a higher concentration of yellow particles, look at both the number of yellow particles and the volume of the solvent in each container. Use the concentration formula to find the number of yellow particles per milliliter. Solution A has more yellow particles per milliliter. So, Solution A has a higher concentration of yellow particles.
Not supported with pagination yet
Which word would you find on a dictionary page with the following guide words? celebrate - cobbler
[ "chair", "crocodile" ]
0
closed choice
grade8
language science
reference-skills
Reference skills
Use guide words
Guide words appear on each page of a dictionary. They tell you the first word and last word on the page. The other words on the page come between the guide words in alphabetical order. To put words in alphabetical order, put them in order by their first letters. If the first letters are the same, look at the second letters. If the second letters are the same, look at the third letters, and so on. If one word is shorter, and there are no more letters to compare, then the shorter word comes first in alphabetical order. For example, be comes before bed.
Put the words in alphabetical order. Since chair is between the guide words celebrate - cobbler, it would be found on that page.
Which country is highlighted?
[ "Trinidad and Tobago", "Barbados", "Dominica", "The Bahamas" ]
3
closed choice
grade6
social science
geography
The Americas: geography
Identify and select countries of the Caribbean
This country is The Bahamas.
Not supported with pagination yet
Which word would you find on a dictionary page with the following guide words? taxi - tie
[ "trestle", "therefore" ]
1
closed choice
grade3
language science
reference-skills
Reference skills
Use guide words
Guide words appear on each page of a dictionary. They tell you the first word and last word on the page. The other words on the page come between the guide words in alphabetical order. To put words in alphabetical order, put them in order by their first letters. If the first letters are the same, look at the second letters. If the second letters are the same, look at the third letters, and so on. If one word is shorter, and there are no more letters to compare, then the shorter word comes first in alphabetical order. For example, be comes before bed.
Put the words in alphabetical order. Since therefore is between the guide words taxi - tie, it would be found on that page.
Not supported with pagination yet
Select the one animal that has all of the monotreme traits listed above.
[ "Echidnas are covered in fur and spines. Their spines help protect them from predators. When an echidna is scared, it curls up into a ball! Echidnas lay eggs and feed their offspring milk.", "Adult tiger salamanders have moist, smooth skin with stripes. They live in burrows underground, but they begin their lives in water. Young tiger salamanders hatch from eggs with no shells underwater." ]
0
Monotremes are a group of animals with similar traits. The following traits can be used to identify monotremes: They make eggs with shells. They have fur or hair. Observe the animals and read the descriptions.
closed choice
grade5
natural science
biology
Classification
Use evidence to classify animals
Scientists sort animals with similar traits into groups. This is called classification. Classification helps scientists learn about how animals live. How do scientists classify animals? First, they make observations about an animal. Scientists observe the animal's traits, including its body parts and behavior. Then, scientists compare the animal's traits to other animals' traits. Scientists classify animals with similar traits into a group.
To decide if an animal is part of a group, look at the traits of the group. Monotremes have the following traits: They make eggs with shells. They have fur or hair. Compare each animal's traits to the group's traits. Select the animal with traits similar to the group's traits. An echidna has the following traits: It makes eggs with shells. It has fur. An echidna has the traits of a monotreme. An echidna is a monotreme. A tiger salamander has the following traits: It spends part of its life in water and part on land. It has moist skin. It makes eggs with no shells. A tiger salamander does not have all of the traits of a monotreme. A tiger salamander is an amphibian.
Not supported with pagination yet
Is this a run-on sentence? Overcome with joy, Mrs. Fischer told her husband the exciting news about her promotion.
[ "yes", "no" ]
1
yes or no
grade12
language science
writing-strategies
Sentences, fragments, and run-ons
Identify run-on sentences
A sentence is a group of words that expresses a complete thought. The band I'm in has been rehearsing daily because we have a concert in two weeks. A run-on sentence is formed when two sentences are run together, joined by just a comma or by no punctuation at all. If only a comma is used, the run-on is called a comma splice. The band I'm in has been rehearsing daily, we have a concert in two weeks. The band I'm in has been rehearsing daily we have a concert in two weeks. There are several ways to fix a run-on sentence: Use stronger punctuation, such as a period or a semicolon. The band I'm in has been rehearsing daily. We have a concert in two weeks. The band I'm in has been rehearsing daily; we have a concert in two weeks. Use a comma and a coordinating conjunction to create a compound sentence. Coordinating conjunctions include and, but, or, and so. The band I'm in has been rehearsing daily, and we have a concert in two weeks. Use a subordinating conjunction or a relative pronoun to create a complex sentence. Subordinating conjunctions include after, although, as, because, before, if, since, unless, until, when, and while. Relative pronouns include that, which, who, whom, and whose. The band I'm in has been rehearsing daily since we have a concert in two weeks.
This is not a run-on sentence. It is not formed from two sentences that have been run together without appropriate punctuation. Overcome with joy, Mrs. Fischer told her husband the exciting news about her promotion.
Not supported with pagination yet
What is the mass of a guitar?
[ "7 tons", "7 ounces", "7 pounds" ]
2
Select the best estimate.
closed choice
grade4
natural science
units-and-measurement
Units and measurement
Choose customary units of mass
Measurements are written with both a number and a unit. The unit comes after the number. The unit shows what the number means. Mass is a measurement of how much matter something contains. There are many different units of mass. When you are using customary units, mass may be written with units of ounces, pounds, or tons. There are 16 ounces in 1 pound and 2,000 pounds in 1 ton. So, 1 ounce is less than 1 pound and much less than 1 ton. A slice of bread has a mass of about 1 ounce, while a can of beans has a mass of about 1 pound. A small car has a mass of about 1 ton.
The best estimate for the mass of a guitar is 7 pounds. 7 ounces is too light and 7 tons is too heavy.
Which of these cities is marked on the map?
[ "Atlanta", "Houston", "New Orleans", "Memphis" ]
3
closed choice
grade4
social science
geography
Cities
Cities of the Southeast
The city is Memphis, Tennessee. New Orleans, Houston, and Atlanta are marked with gray circles on the map below.
Which country is highlighted?
[ "Cuba", "Haiti", "Jamaica", "Trinidad and Tobago" ]
2
closed choice
grade6
social science
geography
The Americas: geography
Identify and select countries of the Caribbean
This country is Jamaica.