地球的力量

Since humans evolved, it's ice, through glaciers, ice sheets and floods,
随着人类的进化，正是冰层，通过冰河，冰原和洪水方式
that has been the dominant force shaping our planet.
强行修整我们的星球
But the greatest influence of ice relies on far more than brute force.
然而冰层最大的影响力莫过于其残忍的威力

That's because ice has some unusual properties that have a profound effect on the Earth's climate.
因为冰层有些非凡的道具 它们深深的影响着地球的气候
I am on the west coast of Greenland in what's known as Iceberg Alley.
我正处在格陵兰岛西海岸著名的冰山巷中
This is the biggest iceberg factory in the world.
这里是世界上最大的冰山制造工厂
I've never been up this close to icebergs before.
我从未如此的接近冰山
I know they're chunks of glacier
这些是巨大的冰块
that fall off the front of the ice sheet and they float here,
它们从前面的冰原掉落然后飘到这里
but when you get this close,
然后当你靠近它们
they're like majestic beautiful ships flowing silently by.
它们就像是庄严美丽的船只静静的从你身边使过
This is known as an iceberg nursery.
而这里就是冰山托儿所
Most substances are denser when solid than when liquid
多数物质在固体状态下比液体状态下密度大
which means they sink. Ice is an exception.
这就意味着会下沉，可是冰块恰恰反向
Because it expands when it freezes, it becomes less dense and so it floats.
因为当冰块冻结的时候体积变大，密度变小，因此能够漂浮
It's also dazzlingiy bright, which makes it highly reflective,
这也令冰块能够高度反光，看起来明亮耀眼
and this combination has a dramatic effect on the Earth's climate.
这种化合物会对地球气候产生重要影响

重点讲解

1、evolve
进化；演变
The bright plumage of many male birds has evolved to attract females.
很多雄鸟进化出鲜艳的羽毛是为了吸引雌鸟。
Maize evolved from a wild grass in Mexico.
玉米是从墨西哥的一种野生禾本植物进化而来的。
（使）逐步发展;（使）演化
a tiny airline which eventually evolved into Pakistan International Airlines.
最终发展成巴基斯坦国际航空公司的一家小型航空公司
Popular music evolved from folk songs.
流行音乐从民歌演变而来。
2、dominant
占支配（或统治）地位的;占优势的;显著的
a change which would maintain his party's dominant position in Scotland.
将使他的政党在苏格兰继续占据支配地位的变化
She was a dominant figure in the French film industry.
她在法国电影界是个举足轻重的人物。
(基因)显性的，优势的
Because it is carried by a dominant gene, an affected individual can expect about half of his or her children to inherit the illness.
因为它是由显性基因携带，所以感染者的孩子会有约50％的可能性遗传该疾病。