问题

Must we clean the classroom now—-No, you _________. It _________ after school.
A:needn’t, must be cleaned
B:mustn’t, needn’t be cleaned
C:needn’t, can be cleaned
D:don’t have to, may clean;
B:mustn’t, needn’t be cleaned
C:needn’t, can be cleaned
D:don’t have to, may clean;
正确答案是: