—Sorry, Mr. Wang. I didn’t finish the assignment yesterday.
Oh, you have done it as yesterday was the deadline.
A. must
B. mustn’t
C. should
D. shouldn’t
网友回答
A. must
B. mustn’t
(答案→)C. should
D. shouldn’t
解析：考查情态动词用法must have done一定做了某事； Should have done本应该做某事实际上却未做。句意：你本应该昨天就完成的，因为昨天是最后期限。