— Guess what! I have won the first prize in the speaking competition. — Congratulations!

问题补充：

— Guess what! I have won the first prize in the speaking competition.

— Congratulations! You put a lot of work into it.

A. should

B. must

C. should have

D. must have

答案：

A. should

B. must

C. should have

D. must have

解析：考查情态动词。句意 猜猜看，我记得演讲比赛第一名。祝贺你，你肯定是投入很多精力在这上面。根据上文提到已经取得成功，故表示对过去的肯定推测 ，所以选D项。

考点 :考查情态动词