battle their way for hundreds of miles upstream. 奋力逆流而上数百英里
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
Black fly larvae anchor themselves with the ring of hooks, 蚋的幼虫靠钩环固定自己
In their upper reaches, mountain streams are full of energy. 上游地段的山涧充满活力
it will travel hundreds of miles to the sea. 行程数百英里回到大海
There is a tropical downpour here almost every day of the year. 这里全年几乎每天都会降下热带暴雨
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
Moisture rising as water vapour from the surface of the sea 水蒸发成水蒸气从海面升起