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

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 stuckB. might stuckC. might have been stuckD. must have stuck

答案：

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。