问题补充：
—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
答案：
A. must
B. should
(答案→)C. must have
D. should have
解析：“你猜到了吗？我的论文得了A”“太好了，你一定进行了大量阅读而且投入了许多工作。”根据语境I have got A for my term paper.可知“已经拿到了好成绩”是过去的事情，对过去的推测用must have done。故选C
