—Perhaps John's not in.
— .Look，the light's on.
A. Yes，he can be at home
B. No，he couldn't go out
C. Yes，he must be at home
D. No，he needn't go out
网友回答
A. Yes，he can be at home
B. No，he couldn't go out
(答案→)C. Yes，he must be at home
D. No，he needn't go out
解析：由“Look，the light's 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”。