Study of strata behavior of Driving the Roadway along Goaf in longwall with top-caving mining face of coal seams with extra-thickness and softness是什么意思_Study of strata behavior of Driving the Roadway along Goaf in longwall with top-caving mining face of coal seams with extra-thickness and softness在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句