—I expected him to be nervous before his speech but he was as cool as a cucumber.—He it

问题补充：

—I expected him to be nervous before his speech, but he was as cool as a cucumber.

—He it carefully.

A. could have prepared

B. shouldn’t have prepared

C. must have prepared

D. can’t have prepared

答案：

A. could have prepared

B. shouldn’t have prepared

(答案→)C. must have prepared

D. can’t have prepared

解析：考查情态动词+完成式的用法：A.could have done过去可能做了什么B. shouldn’t have done本不该做而做了， C. must have done一定已经做了，D. can’t have done过去不可能做了，句意：--我以为他在演讲前紧张，但是他很冷静。--他一定准备的很充分。选C.