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
but every year some of the world's high rivers are crowded by millions of visitors. 而世界上的高山河流每年都将 迎接成千上万的来访者
they're still held by a silicon safety line. 它们还有一根坚韧的“安全索”
Here, strange towers of sandstone have been sculptured over the millennia by battering wind and torrential rain. 这里伫立着数千年来暴风骤雨 雕凿成的奇形怪状的石塔
The flock stay in close contact by calling one another. 鹤群通过互相鸣叫保持密切联系
By late morning ferocious winds are roaring past the peaks. 晌午时分 群山间狂风大作
By midsummer its larger, more famous relative, has retreated into a cave. 到了仲夏 它那更大更有名的亲戚 便会躲进山洞
but the panda is held captive by its diet 只有大熊猫因为食物始终逗留此地