Mary must have gone to the cinema when I went to see her yesterday,__?A.didn't sheB.mustn't shewhy we choose A
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 done表示对过去的猜测
答
must 做情态动词时只用在肯定句，不能用在否定和疑问句中。
所以，这里的反义疑问句只能借助于助动词did。
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...