A primary programme of ventilation for the deep part of east mining district, which is instructive to the practice.

并对今后东部矿区深部采矿综合通风系统提出初步方案，有现实指导意义。

youdao

A primary programme of ventilation for the deep part of east mining district, which is instructive to the practice.

并对今后东部矿区深部采矿综合通风系统提出初步方案，有现实指导意义。

youdao