They must be there now,aren't they?这里为什么不是mustn't they而是aren't they?

问题描述:

They must be there now,aren't they?这里为什么不是mustn't they而是aren't they?

这里应该填aren't they而不是mustn't they,因为这句话的意思是:他们现在一定在这里,难道不是吗?aren't 的意思是难道不是吗 而mustn't 的意思是没有必要的