问题描述:
There's no light on.they____be at home.
A:can't B:mustn't C:needn't D:shouldn't
为什么用can't,而不用mustn't.mustn't不是表推测吗?
A:can't B:mustn't C:needn't D:shouldn't
为什么用can't,而不用mustn't.mustn't不是表推测吗?
问题解答:
我来补答展开全文阅读