Mary must have gone to the cinema when I went to see her yesterday,__?
问题描述：
Mary must have gone to the cinema when I went to see her yesterday,__?
A.didn't she
B.mustn't she
why we choose A
答
must have gone 这里的 must + 完成时态 ,表示 猜测还原：Mary went to the cinema when I went to see her yesterday,didn't she?肯定：must have done否定：cant have done可能：may have done以上是对过去时的猜...