54. --- I have two suggestions: one is to go to the cinema, the other is to have a drink.

--- Well, personally I prefer the _____ one. I don’t like films very much.

A．late

B．latter

C．latest

D．Last

对于化学反应A+B===C+D，下列说法错误的是 [ ]

A. 若A为碱，B为酸，则该反应一定是复分解反应

B. 若A和C都是单质，B和D都是化合物，则该反应一定是置换反应

C. 若A、B、C、D都是化合物，则该反应一定是复分解反应

D. mgA和ngB充分反应，则生成C和D的质量总和不大于（m+n）g