【题目】—The expression on his face suggests he ________ have failed in the competition.
—I guess so. It’s not easy after all.
A. should B. could
C. must D. might
在线课程【答案】C
【解析】考查情态动词。此处must have done sth.表示对过去事情有把握的推测。句意：——他的面部表情表明他一定比赛失败了。——我想是吧。考试毕竟不容易。