-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
【正确答案】：D
【题目解析】：【考点点击】本题考查附加疑问句中尾句部分的助动词用法。【要点透析】 must bbe结构中的中心词应为be,且 He must be in the lab相当于 think he is in thelab,故其尾句部分为isn'the
