must have done 表示对过去的推测,如果句中无过去的时间状语,反意问句就用haven't/hasn't +主语.如 He must have finished his homework,hasn't he
如果句子中有过去的时间状语,后面的反意问句就用didn't +主语,如
He must have gone to the cinema last night ,didn't he
must have done 表示对过去的推测,如果句中无过去的时间状语,反意问句就用haven't/hasn't +主语.如 He must have finished his homework,hasn't he
如果句子中有过去的时间状语,后面的反意问句就用didn't +主语,如
He must have gone to the cinema last night ,didn't he