目的了解煤矿井下作业噪声危害现状，探讨防治对策。

Noise hazard of coal mine operation is serious, and needs comprehensive control.

youdao

目的了解煤矿井下作业噪声危害现状，探讨防治对策。

Noise hazard of coal mine operation is serious, and needs comprehensive control.

youdao