The teacher ___ do all the exercises,but a pupil____.A.needn't;must B.may not;must答案是A,为什么

问题描述:

The teacher ___ do all the exercises,but a pupil____.A.needn't;must B.may not;must答案是A,为什么

needn't 不必 must 必须 老师什么练习都不必做,但是学生必须做.大概是这个意思~