1 . 濫采
2. gothitegophering濫采goths 煤的突出
2 . 不規(guī)則勘探
gopherhole 穿索孔, gophering不規(guī)則勘探, gopherhole 鼠洞式孔
3 . 掠奪性開采
gophering不規(guī)則勘探, gophering掠奪性開采, gophering不規(guī)則開采
4 . 不規(guī)則開采
gopherhole 鼠洞式孔, gophering不規(guī)則開采, gophering不規(guī)則勘探