–MayIgotothecinema,Mum? --Certainly.Butyou

问题详情：

 –May I go to the cinema, Mum?  --Certainly. But you ______ be back by 11 o’clock.

       A. can             B. may             C. must            D. need

【回答】

C

知识点：情态动词

题型：选择题