—Why is Tom absent?—He must be sick ?A. isn’t heB. must heC. is heD. mustn’t he

问题补充：

—Why is Tom absent?

—He must be sick，?

A. isn’t he

B. must he

C. is he

D. mustn’t he

答案：

(答案→)A. isn’t he

B. must he

C. is he

D. mustn’t he

解析：此处是对现在的情况进行推测，附加疑问句要用isn’t he?