电烙铁使用久了容易出现（）现象。
A、温度低
B、过热
C、不热
D、电流大
参考答案：B
Tim's mum is worried _______ her son's eyesight as he always plays
online games.
A. for
B. about
C. with
D. of
引起痛痹最主要的外邪是（）
A.风邪
B.寒邪
C.湿邪
D.热邪
E.燥邪
