Division of Danger Zone and Safety Zone in No.9 Coal Bed on Mining Under Safe Water Pressure of Aquifer in Xiyu Coal Mine of Taiyuan City是什麼意思_Division of Danger Zone and Safety Zone in No.9 Coal Bed on Mining Under Safe Water Pressure of Aquifer in Xiyu Coal Mine of Taiyuan City在線翻譯_英語_讀音_用法_例句