问题补充：
I can’t find the recorder in the room. It by someone.
A. may take
B. may have been taken away
C. must have taken away
D. needn’t have been taken away
答案：
A. may take
(答案→)B. may have been taken away
C. must have taken away
D. needn’t have been taken away
解析：情态动词考查题。 must have done 一定做了某事， 在房间里我找不到录音机肯定有人拿走了。 选B
