- 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 - For the past 5 million years
在过去的500万年中 - Arizona's Colorado river has eaten away at the desert's sandstone
亚利桑那州的科罗拉多河 冲走了大量沙石 - to create a gigantic canyon.
形成一个巨大深邃的峡谷 - It's over a mile deep
它的深度超过1英里 - and at its widest it's 17 miles across.
最宽的地方达17英里 - The Grand Canyon.
这就是大峡谷