coal mining
短语词组
- coal -mining methods 采煤方法
- coal surface mining 露天采煤
- single coal seam mining 单一煤层开采
- coal resources mining 煤炭资源开采
- coal pillar mining 带煤柱开采
- coal mine mining 矿井开采
- coal caving mining 煤采煤;放顶煤开采;放顶煤
- opencast coal -mining 露天采煤 返回 coal mining