Someone is knocking at the door.Who it be?— It be Tom.He is still in the school.A.can,can't B.can,mustn't C.might,could D.might,may 为什么B不可以 mustn't不是更加肯定吗?
问题描述:
Someone is knocking at the door.Who it be?— It be Tom.He is still in the school.A.can,can't B.can,mustn't C.might,could D.might,may 为什么B不可以 mustn't不是更加肯定吗?
答
这里是表示推测,表推测否定一般情况下都使用can't .mustn't是指禁止,绝对不可以.must可以表推测,但mustn't 一般不可以表推测,一般用于祈使句或请求语境.