When questions in class, one should answer them as clearly as possible.
A. asking
B. to ask
C. to be asked
D. asked
网友回答
A. asking
B. to ask
C. to be asked
(答案→)D. asked
解析： 本题考查省略。句意：课堂上被提问时，应尽可能清楚地回答。本句前半句实际上是when one is asked questions in class的省略。C项表示“将要被提问”，不合乎语境。