短语词组短语steep down grade 陡下坡steep -grade mine 急倾斜矿井steep p grade 急倾斜culvert on steep grade 陡坡涵洞steep grade mining 陡帮开采sustained steep grade 持续陡坡a steep grade 陡坡long steep grade 长大坡度Hurley Steep Grade T -Shirt 赫利陡坡 返回 steep grade