Question

--______ we clean the classroom at once?
--No, you _____. You____ clean it after school.

A．Must, needn’t, may	B．Must, mustn’t, can
C．Shall, can’t, must	D．Need, mustn’t, may

Answer 1

A

考查情态动词.must必须,否定回答一般借助于needn’t或者don’t have to.shall一般用将来时态,need需要.句意:我们必须现在就打扫教室吗？不，你们不必。你们可以放学后在打扫。故选A。