问题
选择题
—We are worried about Tom. Why hasn’t he come back?
—Don’t worry. He ______ in a traffic jam.
A．might be caught
B．may have been caught
C．can have been caught
D．should have been caught
答案
答案：B
题目分析：考查情态动词+完成式的用法：句意：--我们很担心汤姆。为什么他还没有来？--别担心，他有可能遇到交通堵塞了。May have done过去可能做了…，因为是be caught in“遇上了”，can 表示对过去的推测，一般用于否定和疑问句中，should have done过去本应该做却没有做，选B。