情态动词的被动语态构成：情态动词+be+过去分词

　　例：I can′t find the recorder in the room. It _____ by somebody.

　　A. must have taken B.may have taken C.may have been taken D.should have been taken

　　【答案】C

　　此题考察的是综合知识点。首先是被动语态，录音机被人拿走了。另外还考察了情态动词加完成式表示对过去时间的推测。