It is life that altered the atmosphere.

是生命改变了大气
Plant life fed off the sun's energy,

植物以太阳能为生
Which enabled it to break apart the water molecule...

这使它能够分解水分子
And take the oxygen.

从中产生氧气
And oxygen filled the air.

从此空气中出现了氧
The earth's water cycle is a process of constant renewal.

地球的水循环是一个持续更新的过程
Waterfalls, watervapor,

瀑布水蒸气
Clouds, rain, springs,

云雨溪流
Rivers, seas, oceans, glaciers.

河海洋冰川
The cycle is never broken.

这一循环从未被打破
There's always the same quantity of water on earth.

地球上的水含量是恒定的
All the successive species on earth have drunk the same water.

地球上相继出现的物种喝的是相同的水