— Guess what! I have got A for my term paper.
— Great! You read widely and put a lot of work into it.
A. must
B. should
C. must have
D. should have
网友回答
A. must
B. should
(答案→)C. must have
D. should have
解析：考查情态动词。根据语境，你一定阅读广泛是过去发生的事情，故用情态动词+have done的结构。must have done过去一定做过某事; should have done本应当做某事。故选C。