高中情态动词

问题描述:

高中情态动词
-That must be a terrible mistake .-No.I don't think it __a mistake .A.must be B.mustn't be C.can be D can't be,

c
think否定提前变成don't think了
can't 否定推测
must表猜测不能用否定,只能用于肯定中