Determination on rational parameters of fully mechanized coal mining blocks in seams with soft roof, soft coal and soft floor in Huaibei mining area是什么意思_Determination on rational parameters of fully mechanized coal mining blocks in seams with soft roof, soft coal and soft floor in Huaibei mining area在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句