井下临时停风的地点，必须切断电源，设置栅栏，揭示警标，并向上级汇报。
参考答案：对
单项填空
One of the best ways for people to keep fit is to ________healthy eating habits.[ ]
A. grow
B. develop
C. increase
D. raise
简述“九品中正制”及“寒门掌机要”。
