 However, to build an intelligent assistant that recommends commonly composed charts, the fundamental problems of "multi-dialect" unification , imbalanced data and open vocabulary exist .
<clarity>  However, to build an intelligent assistant that recommends commonly composed charts, the fundamental problems of "multi-dialect" unification , imbalanced data and open vocabulary exist .
 However, to build an intelligent assistant that recommends commonly composed charts, it should take the challenges of efficiency , imbalanced data and open vocabulary exist .