问题补充:
—Must I make a phone call to him now?
—No, you. You write an email.
A. mustn’t; may
B. may not; must
C. shouldn’t; must
D. don’t have to; may
答案:
A. mustn’t; may
B. may not; must
C. shouldn’t; must
(答案→)D. don’t have to; may
解析:must的否定回答,一般用needn’t或者don’t have to,据此即可判定本题选D。