---I wonder why Mr Green hasn’t showed up at the meeting yet.　　---I’m not sure but he in

问题补充：

---I wonder why Mr Green hasn’t showed up at the meeting yet.

---I’m not sure, but he in a traffic jam driving here.

A. could be stuck

B. might stuck

C. might have been stuck

D. must have stuck

答案：

A. could be stuck

B. might stuck

(答案→)C. might have been stuck

D. must have stuck

解析：表示对过去已经发生事情的推测应该用情态动词的完成时形式，但might的可能性不大；结合上下文的意思可以知道应该用被动形式。