Keep looking—they can't just have vanished off the face of the earth.
继续找—他们不可能就此从地球上彻底消逝的。
Even if bacteria did arrive on Earth from Mars, they must have died out.
即使细菌真的从火星来到地球，它们也一定已经灭绝了。
It will let us eliminate the risk we would take of contaminating the samples if they were brought back to Earth.
如果他们被带回地球，会使我们消除可能为样品污染而承担的风险。
When you analyze this light, you can figure out their distance from the Earth, and identify what they are made of, determine their chemical composition.
当你分析这些光的时候，你可以计算出它们与地球的距离，并确定它们由什么构成，查明它们的化学成分。
They live in precarious balance and one of the toughest environments on earth.
他们生活在不稳定的平衡中，并且这是地球上最艰苦的环境之一。
They wouldn't even have been able to get started without earth science understanding—knowledge about wind, storms, meteorology.
如果没有对地球科学的了解——关于风、风暴、气象学的知识，他们甚至不可能起步。
Since most violent events on Earth occur randomly, nobody can predict when or where they will happen.
由于地球上大多数的暴力事件都是随机发生的，没有人能预测它们将在何时何地发生。
They actually account for almost all of the meteorite material that falls to earth.
它们实际上在落在地球上的陨石物质中占了接近总数。
They bear a strong resemblance to river systems on Earth, and geologists think that they are dried-up beds of long-gone rivers.
它们与地球上的河流系统非常相似，地质学家认为它们是早已消失的河流留下的干涸的河床。
They hope the new materials are both comfortable and good for the earth.
他们希望新材料既舒适又对地球有益。
They banked the earth (up) into a mound.
他们把土堆成一个土丘。
They are to attempt to be the first to circle the Earth non-stop by balloon.
他们将试图成为首批乘热气球不间断环球飞行的人。
They shunned the belief that there is a link between the alignment of the planets and events on the Earth.
他们回避了在行星的排列和地球上发生的事件之间有联系的看法。
It also slows down more as you move faster, which means astronauts some day may survive so long in space that they would return to an earth of the distant future.
当你移动得更快时，它的速度也会减慢，这意味着有一天宇航员可能会在太空中生存很长时间，以至于在遥远的将来他们才会回到地球。
They also think they can explain the bright flash seen from the earth earlier this month: it was a meteor, though a small one that didn't get very far.
他们还认为他们可以解释本月早些时候，从地球上看到的明亮闪光，尽管是很小的一颗流星，但没有飞多远。
I think it is so stupid of people to do bad things to the earth that they are living on! I can't understand why they are doing these. People should care about the environment.
我认为人类在破坏他们赖以生存的地球是愚蠢的！我不明白他们为什么这么做。人类应该关心环境。
他们烧掉了土地。
They were busy carrying earth.
他们正忙着担土。
They are so busy and having such fun under the earth or in the trees or heather.
它们很忙，在地下、树上或石楠花丛里玩得很开心。
I think that even Swiss children are made to touch the earth, otherwise they would have to have wings.
我认为即使是瑞士的孩子也会沾上泥土的，否则他们就得有翅膀了。
The Roses have been in the earth, and they say no.
玫瑰花们曾去过地下，它们说没有。
They behaved as if they were on Earth.
他们表现得就像在地球上一样。
They are working in the earth now—pushing up pale green points because the spring is coming.
它们现在正在土壤里使劲儿——把嫩绿的芽拱出来，因为春天就要来了。
One step in its formation on Earth involves microorganisms; they actually speed up the formation of jarosite dramatically.
在地球上形成黄钾铁矾的其中一个步骤涉及到微生物；实际上，微生物能大幅加快黄钾铁矾的形成。
If the Sun was at the center of the universe, things would fall toward the Sun and away from the Earth, which of course they didn't.
如果太阳在宇宙的中心，物体就会离开地球向太阳落去，但事实显然没有。
Very thrilling stories they were, too, to an earth-dwelling animal like Mole.
对于鼹鼠这样一个住在地球上的动物来说，这些故事也是非常令人激动的。
Six earth-worms shone as well as they could.
六只萤火虫尽其所能地发光。
They represent the earth coming back to life and best wishes for new beginnings.
它们代表着大地的复苏和对新开始的美好祝愿。
They believe that crocodiles made the earth and its people.
他们认为鳄鱼创造了地球以及它的子民。
When people began to realise that there was not enough oil on the earth, they asked car makers to produce more efficient and less polluting cars.
当人们开始意识到地球上没有足够的石油时，他们要求汽车制造商生产能效更高、污染更少的汽车。
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