deep mining of coal pillar
英
美
deep mining of coal pillar的用法和樣例:
例句
- Most of large and middle scale open-pit mines in China have reached deep mining.
摘要我國的大多數大中型露天礦山已經(jīng)或即將進(jìn)入深部開(kāi)采。
deep mining of coal pillar的相關(guān)資料:
臨近單詞
国内精品美女A∨在线播放xuan