问题描述: Must we hand in our homework now?No,you needn't.解释一下为什么要用needn't. 1个回答 分类:英语 2014-10-30 问题解答: 我来补答 Must 否定回答用 needn't ( 没有必要)而:mustn't 表示禁止“一定不要”,如:You must play football in the street. 展开全文阅读