Question

【题目】—It’s already 11 o’clock , and he ______ have been here half an hour ago.

—Maybe he got caught in the rain.

A. must B. ought to

C. may D. can

Answer 1

【答案】B

【解析】

考查情态动词。句意：已经11点了，他半小时前就该到了。A. must have done必定做了…（表示对过去的推测）；B. ought to have done 本应该做的；C. may have done可能已经做过某事；D. can have done本来可以做的（但没有做），根据题意，故选B。