-- Perhaps Tom’s not in.-- . Look the light’s on.A. Yes he can be at homeB. No he mustn

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。