问题补充:
Mary is so wet. She in the rain.
A. must be caught
B. must have been caught
C. should have been caught
D. can have been caught
答案:
A. must be caught
(答案→)B. must have been caught
C. should have been caught
D. can have been caught
解析:
这题考查情态动词表示对过去情况的推测的用法,根据Mary is so wet.玛丽淋湿了,推测一定是过去遭雨了,must have done 就是对过去的肯定推测。所以选B。