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  3. The balance of nature is a very elaborate and very delicate system of checks

The balance of nature is a very elaborate and very delicate system of checks

游客2024-12-30  5
问题    The balance of nature is a very elaborate and very delicate system of checks and counterchecks. It is continually being altered as climates change, as new organisms evolve, as animals or plants permeate to new areas. But tile alterations have in the past, for the most part, been slow, whereas with the arrival of civilized man, their speed has been multiplied manifold: from the evolutionary time-scale, where change is measured by periods of ten or a hundred thousand years, they have been transferred to the human time-scale in which centuries and even decades count.
  Everywhere man is altering the balance of nature. He is facilitating the spread of plants and animals into new regions, sometimes deliberately, sometimes unconsciously. He is covering huge areas with new kinds of plants, or with houses, factories, slag-heaps and other products of his civilization. He exterminates some species on a large scale, but favors the multiplication of others. In brief, he has done more in five thousand years to alter the biological aspect of the planet than has nature in five million.
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答案 自然界的平衡是一个非常微妙又异常脆弱的破坏与反破坏的体系。这种平衡随着气候的变化，新生物的进化，以及动植物向新领域的蔓延而不停的变化着。但这种变化在以前，或者说很久以前是缓慢的，随着文明人类的到来，变化的速度就急速地提高了：进化速度由以前儿万年甚至十万年为计算单位提高到现在的以几百年甚至几十年为单位。
  人类正无处不在地改变着大自然的平衡。人们有意或无意地使动植物向其他领域扩展变得更加容易。大片的土地被覆盖上了新的各种各样的植物，或者是楼房，工厂，一堆堆的矿渣和其他人类文明的产物。人类使一些物种大规模的灭绝，而又倾向于使另一些物种大量地繁衍。总之，人类在五千年内使地球的生物圈发生的变化远远大于大自然自身五百万年里所发生的变化。
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