—Perhaps Johns not in.—.Look the lights on.A. Yes he can be at homeB. No he couldnt go

问题补充：

—Perhaps Johns not in.

—.Look，the lights on.

A. Yes，he can be at home

B. No，he couldn go out

C. Yes，he must be at home

D. No，he needn go out

答案：

A. Yes，he can be at home

B. No，he couldn go out

(答案→)C. Yes，he must be at home

D. No，he needn go out

解析：由“Look，the lights on”可知他此刻一定在家里，所以用must be at home表示“对事情的肯定推测”。