—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：考查虚拟语气。句意：你猜怎么着？我的学期论文得了个A。——太棒了。你一定广泛的阅读了，并且投入了很多工作吧！“must+have+done”表示对过去事情的肯定推测，译成“一定做过某事”，本题中read是过去分词，故选C。