This river has cut the world's longest canyon system - 这条河冲蚀出了世界上最长的峡谷系 a 1,000 mile scar clearly visible from space. 在太空中也能清楚地看到 这条长达1000英里的沟壑 As rivers leave the mountains behind, 河流离开山区之后 they gradually warm and begin to support more...
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 gi...
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...
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 Cany...
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 This river has cut the world's longest canyon system - 这条河冲蚀出了世界上最长的峡谷系 a 1,000...
The annual arrival of spawning salmon 鲑鱼每年都会到河里产卵 brings huge quantities of food into these high rivers that normally struggle to support much life. 于是这些平常只能勉强维持众多动物生计的 高山河流终于有了提供饕餮大餐的机会 Although relatively lifeless, the power of the upland...
brings huge quantities of food into these high rivers that normally struggle to support much life. 于是这些平常只能勉强维持众多动物生计的 高山河流终于有了提供饕餮大餐的机会 Although relatively lifeless, the power of the upland rivers to shape the landscape 尽管高山河流的生物量相对较少 它们却有...
Although relatively lifeless, the power of the upland rivers to shape the landscape 尽管高山河流的生物量相对较少 它们却有能力改变地形 is greater than any other stage in a river's life. 在河流扮演的角色中 这才是最主要的 Driven by gravity, they're the most erosive forces on...
is greater than any other stage in a river's life. 在河流扮演的角色中 这才是最主要的 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 ea...
he's learnt to dive for his dinner. 它学会了潜水捕猎 But catching salmon in deep water is not that easy 但要想在深水中捕获鲑鱼可不太容易 and the cubs have lots to learn. 熊崽们还要很多东西要学 The annual arrival of spawning salmon 鲑鱼每年都会到河里产卵 brings huge quantities of fo...