题目内容：

must have been done是什么被动语态
如will be done是一般将来时被动语态,can be done是情态动词被动语态

优质解答

首先 must have done 虽然有情态动词 但是他和情态动词无关,他是只对过去发生事情肯定的推测
The ground is wet ,it must have rained last night.
must have been done 过去发生事情肯定的推测,这个动作是被动!
请给分哟