――Wedidnotseehimatthelectureyesterday. ――You

问题详情：

―― 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

【回答】

知识点：虚拟语气与情态动词

题型：选择题