underground mining
短語詞組
- underground col mining 地下採煤
- underground coal mining 地下採煤
- underground E mining 地下開採
- Underground melting mining 地下熱熔開採
- underground d mining 地下採鑛
- underground coal mining method 地下採煤方法
- underground bench mining 井下梯段採鑛法
- underground trackless mining vehicle 地下無軌採鑛車輛 返回 underground mining