— We did not see him at the lecture yesterday — You him since I went to an internationa

问题补充：

— We did not see him at the lecture yesterday．

— You him, since I went to an international conference with him．

A. mustn’t have seen

B. can’t have seen

C. couldn’t see

D. needn’t have seen

答案：

A. mustn’t have seen

(答案→)B. can’t have seen

C. couldn’t see

D. needn’t have seen

解析：考查情态动词。can’t have done不可能做某事。句意：——我们昨天在讲座上没看到他。——你不可能看到他，因为我和他参加一个国际会议。