Fully-mechanized Coal Winning is difficult in the production with complex working face.

综合机械化开采对构造复杂工作面生产具有较高的要求。

youdao

Fully-mechanized Coal Winning is difficult in the production with complex working face.

综合机械化开采对构造复杂工作面生产具有较高的要求。

youdao