These strata are the product of those billions and billions of shells.

这些地层便是数以亿计的贝壳的产物
Thanks to them, the carbon drained from the atmosphere,

多亏他们碳被从大气分离
And other life-forms could develop.

其他生物得以发展
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