High Yield and High Efficency Stoping Technology of Light-duty Support for Caving Coal in the Steeply Inclined and Much Thicker Coal Bed是什麼意思_High Yield and High Efficency Stoping Technology of Light-duty Support for Caving Coal in the Steeply Inclined and Much Thicker Coal Bed在線翻譯_英語_讀音_用法_例句