.
Playing with a cell phone, he suddenly the teacher staring at him.
A. knew of
B. became aware of
C. reflected
D. aware for
网友回答
A. knew of
(答案→)B. became aware of
C. reflected
D. aware for
解析：考查短语辨析。knew of 了解，became aware of 意识到，reflected 反映，句意：他在玩手机，他突然意识到老师正在盯着他。所以选B。