【BBC地球脉动】淡水 02

英语自学网

Fresh water's journey starts here, high in the mountains. Growing from humble streams to mighty rivers it will travel hundreds of miles to the sea. Angel Falls, the highest waterfall in the world. Its waters drop unbroken for almost 1,000 metres. Such is the height of these falls that long before the water reaches the base in the Devil's Canyon it's blown away as a fine mist. In their upper reaches, mountain streams are full of energy. Streams join to form rivers, building in power, creating rapids. The water here is cold. Low in nutrients, but high in oxygen. The few creatures that live in the torrent have to hang on for dear life.淡水旅程就从这些高山开始。它们由涓涓细流变成滔滔大河，奔流千里，最后汇入大海。天使瀑布是世界上落差最大瀑布。它的水流不中断的降落高度近1000米。由于高度太高，瀑布在到达魔鬼峡谷时早就化成了雾被吹走了。在上游段，山间溪流充满活力。溪水汇合成河流，能量加大，速度加快。这儿的水很凉，养份很少，可是氧的含量很高。生活在急流中的为数不多的生物必须努力坚持得住才能生存。