— 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
网友回答
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。