为什么双股轨道提升的斜巷要设置窜钩警铃？

A. 灰色
B. 黑色
C. 浅蓝色
D. 银色

A. 正确
B. 错误

A. treating with oxygen scavengers
B. securing the boiler and giving it a blowing down
C. increasing the pH
D. reducing the phosphate level