---Why hasn’t Jane arrived yet?
---She again in the morning.
A. shouldn’t have overslept
B. may have turned off the alarm clock
C. must have no one to call her
D. should have someone to wake her up
网友回答
A. shouldn’t have overslept
(答案→)B. may have turned off the alarm clock
C. must have no one to call her
D. should have someone to wake her up
解析：考查情态动词的完成式：句意：对不起。我迟到了。我可能是把闹钟关了，又睡回笼觉了。might 表示“有可能...”。 might have done sth. 是常用句型，表示在过去可能做了什么。用should（n’t） have done就表示“过去（不）应该做而没做（做了）”，must have done过去一定做了，选B。