They___ the film at that time a.may see b.mustn't see c.must have_英语解答

They___ the film at that time a.may see b.mustn't see c.must have been d.can have seen
They___ the film at that time a.may see b.mustn't see c.must have been d.can have seen

人气：350 ℃　时间：2019-08-19 20:35:27

解答

C
must have done 一定已经,对发生过的事作以肯定推测