问题补充:
-- Perhaps Tom’s not in.
-- . Look, the light’s on.
A. Yes, he can be at home
B. No, he mustn’t go out
C. Yes, he must be at home
D. No, he needn’t go out
答案:
A. Yes, he can be at home
B. No, he mustn’t go out
(答案→)C. Yes, he must be at home
D. No, he needn’t go out
解析:考查情景交际。“也许汤姆不在家。”“不,他一定在家。看,灯亮着呢。”Yes是Yes, he is的省略;must表示肯定推测,意为“一定”。故选C。