【题目】—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
在线课程【答案】C
【解析】本题考查情态动词的用法。由“have got A”可知是对过去发生事情的推测，故用“情态动词+have done”结构。must have done表示“必定做过某事”，符合题意。