—Must I go to see a doctor when I have a cold?

—No, you _______.

A. don’t B. needn’t C. can’t

—Must I finish the exercise this afternoon?

        —Yes, you ______, but you ______ finish it now.

         A. must, mustn’t                 B. must , don’t have to

         C. may, needn’t                  D. may , mustn’t

---Must I hand in my exercise book now, Mr. Zhao?
---No, you ______. You may give it to me tomorrow.

—Must I finish the homework tonight?
—No, you        .You can finish it tomorrow.

—Must I pay for the bill now, boss?

—No, you __________ pay for it after the meal.

A．needn’t         B．can’t            C．may              D．should