Question

.--- He has to finish the experiment today. He must be in the lab,____?
---That s quite possible.

A．mustn't he

B．won't he

C．doesn't he

D．isn't he

Answer 1

.D

该题考查反意疑问句中尾句部分的助动词用法，must be结构中的中心词应为be，且He must be in the lab 相当于I think he is in the lab，故其尾句部分为isn't he。