Driven by gravity, they're the most erosive forces on the planet. 它们借助地心引力 成为地球上最大的侵蚀力量
and the thickening veil of snow forces them to give up. 雪越下越密 它们只好选择放弃
These same volcanic forces also created Ethiopia's highlands. 这些相同的火山作用 也造就了埃塞俄比亚高原