protective coal seam的意思|示意
保护层
protective coal seam的网络常见释义
解放层 ... 破碎顶板 cracked roof 解放层 protective coal seam 电阻应变仪 resistance strain instument 坑口电厂 pithead power plant ...
protective coal seam相关短语
1、 Mining protective coal seam 开采保护层
2、 extra-thin protective coal seam 极薄保护层
3、 extra-thin protective coal seam drilling 极薄保护层钻采