Understanding this cycle is important, not only because it sustains life on Earth, but also because it is bound up with the rate of global warming.
理解这种循环很重要，不仅因为碳循环维持地球上的生命，而且因为它对于全球变暖的速度有密切关系。
Early life-forms on Earth were confined to the oceans because water was the only available protection they had against ultraviolet radiation.
地球上早期的生命形式被限制在海洋里，因为水是帮助它们抵御紫外线辐射的唯一有效保护。
The finding not only presents the possibility that alternative life forms can exist, or once existed, on Earth.
这一发现不仅显示了地球上可能存在其他类型的生命，或者曾经存在过。
But as the only life we know of exists here on Earth, it's not a bad assumption to make.
但是，作为我们已知的唯一一种存在在地球上的生命，这并不是个荒谬的假设。
It is hard to understand that life on Earth is an illusion, but if you can view it that way and see it as only a passing phase of experience it will have less impact upon you.
确实，要明白地球上的生活是一个幻象是很难的，但是如果你们能够以一种阶段性的体验来看待它，它就只能很少的影响到你。
Not only yours but the life of all human beings on this earth, hoping to escape from it all.
不只是你的，也是这世上所有人的，大家都想从中逃开。
However it came into being, Rees argued, our universe is inherently life-supporting, and there is no reason to believe that that potential has been realized only on Earth.
然而，它形成了人类，里斯辩论道，我们的宇宙是固有的生命支持，并且没理由相信那种潜能已经只在地球上实现。
Of all the planets in our solar system, we are now pretty certain the Earth is the only one on which life can survive.
我们目前可以肯定的是，在我们太阳系的所有行星中，地球是生命能存在的唯一行星。
The only theory, the purpose of life is building a paradise on earth in the earth.
人生惟一理论的目的，是在地上建筑人间天堂。——希尔泰。
There is no shortcut to life on the road, only down to earth.
生命的道路上永远没有捷径可言，只有脚踏实地走下去。
As far as we know, the earth is the only planet with life on it.
就我们所知，地球是唯一的有生命的行程。
It's well-known that the most tenacious of life species on the Earth are cockroaches. They live everywhere if only there in food.
众所周知地球上最顽强的生命种类是蟑螂，他们生活在有食物的任何地方。
The truth is: we have no idea how much life there is on Earth. And we've only just begun even attempting to find out.
事实是：我们根本不知道地球上有多少生命。我们才刚刚开始试图找到答案。
The only problem is that the red giant phase will only last a few hundred million years-not long compared to the billions of years that life on earth has been evolving.
唯一的问题是红巨星阶段仅能持续几亿年-无法与地球早期生命形成时的数十亿年时间相比。
Only this kind of education can really make life reside on the earth admirably and poetically.
这样的教育才能真正让人美感的、诗意般地栖居在大地上。
Of all the planets in our own solar system. we are now pretty certain the Earth is the only one on which life can survive.
在我们自己的太阳系的所有行星中。我们现在相当肯定仅仅地球是有生命存在的那个。
Of all the planets in our own solar system, we are now pretty certain the Earth is the only one on which life can survive.
在太阳系的所有星球中，我们现在能肯定的是地球是我们唯一的生存家园。
Of all the planets in our solar system, we ware now pretty certain the Earth is the only one on which life can survive.
我们目前可以肯定的是，在我们太阳系的所有行星中，地球是生命能存在的唯一行星。
The aliens have lots of questions about life on earth, but the only humans they have to ask are five years old.
外星人虽然有很多问题想问——但是能回答他们问题的只有那些5岁的孩子们。
Nowhere else in the physical universe has life been found. Only on planet Earth have just the right conditions existed.
宇宙其他地方都找不到生命的 迹 象，只有地球才具备维持生命所需的一切条件。
Having lived on Earth for three million years, with a reputation of a "living fossil," the pandas are living a harmonious and sweet life in Chengdu city, the only city home in the world.
在地球上生活了二三百万年，有着“活化石”之称的大熊猫，在成都这个世界上唯一的城市家园里，生活甜美，繁衍生息。
The only problem is that the red giant phase will only last a few hundred million years - not long compared to the billions of years that life on Earth has been evolving.
唯一的问题是红巨星阶段仅能持续几亿年-无法与地球早期生命形成时的数十亿年时间相比。
All people on earth daily drink from the showers of heaven, the only source of life, daily bread, bodily health, and spiritual well-being.
地上万民每天饮用天上降下的雨水，那是生命、每日粮食，以及身心灵健康的唯一源头。
The life on earth boasts not only a brilliant today, miraculous tomorrow, but also an extraordinary and documented past.
地球的生命不仅拥有辉煌的现在，奇迹般的明天，更有一部记录在案的不平凡的过去。
The life on earth boasts not only a brilliant today, miraculous tomorrow, but also an extraordinary and documented past.
地球的生命不仅拥有辉煌的现在，奇迹般的明天，更有一部记录在案的不平凡的过去。
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