Ignition mechanism and its prevention for longwall with top-caving mining face in multi-layers, inflammable, inclined coal face with extra-height是什么意思_Ignition mechanism and its prevention for longwall with top-caving mining face in multi-layers, inflammable, inclined coal face with extra-height在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句