矿井井下（）的空气温度不得超过30℃。
A.进风井口以下
B.机电设备硐室
C.进回风大巷
D.采掘工作面
参考答案：B
The student became ______ the danger of smoking and decided to give it up.
A．aware
B．aware that
C．aware of
D．aware with
