城市化
我来试试,希望你能满意。如果有疑问,636f707962616964757a686964616f31333238653935可以给我发邮件。很高兴与你切磋。oliviaguanchina@hotmail.comIt was once thought that air pollution affected only the area immediately around large cities with factories and/or heavy automobile traffic. today ,we know that although these are the areas with the worst air pollution , the problem is literally worldwide. On several occasions over the past decade, a heavy cloud of air pollution has covered the entire eastern half of the united states and led to health warnings even in rural areas away from any major concentration of manufacturing and automobile traffic. 空气污染曾一度被认为只影响与大城市相毗邻的地区,或者机动车密集地带。现在,我们知道严重空气污染不仅仅存在于上述地区,它已经真正成为全球性的问题。在过去的几十年里发生的污染事件中,有好几次都是厚重的污染空气覆盖了东部半个美国,甚至在远离主要制造工业和机动车集中地的郊区,也因此拉响了危害健康的“警报”。In fact, the very climate of the entire earth may be affected by air pollution. Some scientists feel that the increasing concentration of carbon dioxide in the air resulting from the burning of fossil fuels(coal and oil) is creating a greenhouse effect-holding in heat reflected from the earth and raising the world’s average temperature. If this view is correct and the world’s temperature is raised only a few degrees, much of the polar ice cap will melt and cities such as new york , boston , Miami and new Orleans will be under water.事实上,全球的气候都可能会受到空气污染的影响。有些科学家认为,由于人们燃烧化石燃料(煤和石油),二氧化碳在空气中不断积聚,导致了温室效应——含有二氧化碳的大气吸收地表折射的热量,使得全球平均气温升高。如果这种观点是正确的,那么即使全球气温只升高几度,北极冰盖的大部分将融化,像纽约,波士顿,迈阿密和新奥尔良等城市也会被海水淹没。Another view , less widely held , is that increasing particulate matter in the atmosphere is blocking sunlight and lowering the earth’s temperature-a result that would be equally disastrous. A drop of just a few degrees could create something close to a new ice age, and would make agriculture difficult or impossible in many of our top farming areas. 还有一种少数人的观点,大气中不断增加的微粒物质阻止阳光射入地球,降低了地球的温度,而这同样也是灾难性的后果。地球温度仅下降几度,就会给人类带来又一个“冰河世纪”,给农业发展造成困难,或者在一些现在看来是优质农耕区的地方,农业将无法发展。at present we do not know for sure that either of these conditions will happen (though one recent government report prepared by experts in the field concluded that the greenhouse effect is very likely). Perhaps, if we are very lucky , the two tendencies will offset each other and the world’s temperature will stay about the same as it is now. 目前,我们尚无法确切知道上述两种状况是否会发生(一份由实地考察专家做出的近期政府报告指出,温室效应极有可能发生)。如果万幸,这两种趋势会相互抵消,地球气温也会像现在一样,保持不变。有人曾认为,空气污染不但影响该地区的大城市周边的工厂和重型汽车交通。版今天,我们知道,虽然权这些是最严重的地区,空气污染,这个问题实际上是全球。几次在过去十年中,沉重的云,空气污染水平已覆盖了整个东部地区的一半美国语tates和导致的健康警告,甚至在农村地区远离任何主要集中制造业和汽车交通。事实上,非常气氛整个地球可能受空气污染。一些科学家认为,增加二氧化碳的浓度在空气中因燃烧化石燃料(煤和石油)正在创造一种温室效应控股热反映从地球和提高世界的平均温度。如果这种观点是正确的,是世界上唯一的温度提高几度,大部分将极地冰盖融化和城市如纽约,波士顿,迈阿密和新奥尔良将根据水。另一种意见认为,普遍较少,是增加颗粒物在大气中的拦截了阳光,降低地球的温度,这一结果也同样是灾难性的。下降了短短度可以创建接近一个新的冰河时代,并将使农业很难或根本不可能在我们许多顶端农业区。目前我们不知道为确保这两个条件会发生(尽管最近的一项政府起草的一份报告,该领域的专家得出结论认为,温室效应是非常可能) 。也许,如果我们很幸运,这两个趋势将相互抵消和世界的温度将保持不变,因为它是现在。