题目内容：

如果英语的一句句子中同时出现了情态动词、助动词、be动词的话,这个句子的反义疑问应该怎么改?
比如：1、They must have come to school,
2.He must have watched the TV play the other day,
3.The doctor must have been there the other day,
我主要想知道如何才能得到这些答案?为什么能得到,