Many in the credit industry expect that credit cards will eventually ____ paper money foralmost everypurchase.[ ]

下列句子中，没有语病的一项是( )

John seems puzzled about ________ the question meant.

下列各句子中加横线的成语使用不恰当的一项是

Bob is _______ an English class. Histeacher is talking ________ English.