—Mum,canIgoouttoplaywithmyfriendstonight?—OK,butyou

问题详情：

—Mum, can I go out to play with my friends tonight?

—OK,but you_______ come back before 9 o’clock.

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

【回答】

C

知识点：情态动词

题型：选择题