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种种动物都濒临灭绝的危险境地，有谁关心？ An animal species becomes extinct when it fails to produce enough young is each generation to keep pace with the death-rate. We can tell from fossil evidence in rocks that many living species have become extinct over the millions of years since life began. It is a natural process and extinction is the fate of many animal that has specialized too far to change when its environment changes, or has to compete with a better-adapted and more powerful animal. Because of remarkable technical developments during the past few centuries, man has destroyed or nearly destroyed some species by killing them at such a rate that they couldn't produce enough offspring, or by completely changing their natural environment at surprising speed. 不论何种动物，只要每一代不能繁殖出足够的后代，不能与这种动物的死亡数字相平衡，那么这种动物就会逐渐灭绝。我们从岩石中的化石遗留下的证据中可以辨别出来，自从地球上有生命时开始，在若干个百万年中，有很多动植物的物种已经逐渐地灭绝了。任何一种生性过于特殊化以致于不能随着环境的变化而改变自己的特性的动物，或者是任何一种必须与一种能更好地适应环境而又更加强大的动物相竞争的动物，它们的命运都将是灭绝，这是个很自然的演化过程。由于最近几百年来各项科学技术的迅猛发展，以惊人的速度大量杀死了某些种动物，或以惊人的速度彻底改变了这些动物的生存的自然环境，致使这些动物不能生育繁衍出足够的后代，人类已经消灭了或已经接近于消灭了某些种动物。 A number of examples can be given of the way in which natural environments are being rapidly changed - Amazonia, for instance. There is every likelihood that many species of animals will be made extinct because of these and similar clearances of natural vegetation. Large numbers of animals have been hunted and killed for food. The North American buffalo is a case of the near-extinction of a species through hunting. Often the numbers are so great the hunters may not realize the danger. But even when the danger is widely publicized, the financial rewards for the hunters may be so great that they choose to ignore the threat to the species. Attitudes like this have led to hunters killing animals for furs, for ivory or merely for ornaments. A slight variation on this is when tourists hunt animals for trophies. Magnificent creatures such as lions and tigers have been hunted out of existence in some parts of the world. It is important to realise, though, that animals are sometimes killed out of fear. Big cats are killed in this way. And animals are sometimes killed out of a wish to reduce numbers to help the species to survive. The killing of the Canadian seals is claimed to be for this purpose, and the use of their skins for furs is only a by-product. 可以举出很多很多的例子说明自然生态环境已经被迅速地改变了，亚马逊河流域就是最好的例证。因为在这些地区以及和这些地区相类似的地区，自然界的植物已经被砍伐净尽，许多种动物将完全有可能灭绝。一大批一大批的动物被当作食品而遭猎杀。北美洲的野牛就是因为捕猎而接近于灭绝的物种之一。这些动物的数量非常庞大，以致于猎手们意识不到这些动物会有灭绝的危险。但即使是把这种动物行将灭绝的危险已经广泛地公诸于众，偷猎对猎人们财务上的回报是非常巨大的，以致猎人们选定了对这些物种行将灭绝的危险采取不理不睬的态度。这类态度已经导致了猎人为了获得毛皮、获得象牙或者仅仅是为了用作装饰品就去猎杀动物。与此稍有不同的是，那些旅游观光客错杀动物是为了留作战胜猎物的纪念品。像狮子、老虎之类雄伟的动物在世界有些地区已经灭绝了。然而要注意到，有时人们杀死了动物是由于人们害怕，这一点是很重要的。大猫科的动物就是这样被杀死的。有时杀死一些动物是希望减少一些数目，以便有助于这种动物能生存下去。据说杀死了一批加拿大的海豹就是为了这个目的，而利用海豹皮只是一种副产物而已。 Many people are concerned about animals and wildlife conservation. One way to preserve species under threat of extinction - whatever the cause - is to remove them to zoos and parks and breed them there. There is always the chance that enough offspring will be born to return them one day to their natural environment - provided it still exists, and that hunters don't kill them again! Another method is to protect the animals in their natural environment by creating wildlife reserves and parks and using game wardens to look after them. But the parks are large, the wardens few and the determination of hunters very great. Early in 1980 wardens and hunters clashed in East Africa. The hunters were armed with modern weapons and several people were killed. 许多人都关心动物及野生动植物的保护工作。不管是什么原因造成了灭绝，一种保存遭受灭绝威胁的物种的办法就是把这些物种搬进动植物园里面去，并让这些动植物在那里生息繁衍下来。假如这种动物能存活下来，假如猎手们不再杀死它们，那么等将来它们繁衍出足够的后代之后，总会有这样的机会，总有一天会让它们的大自然的环境中去！另一种在自然环境中保护动物的办法，就是创建野生动植物保护区和野生动植物园并设置禁止渔猎野生动物监督官来看护这些动物。但是野生动植物园范围很广大，禁止渔猎野生动物监督官人手又很少，偷猎野生动物的猎人们的偷猎决心都很大。1980年初监督官与猎手们发生了冲突。猎手们都装备有现代化的武器，结果有数人在冲突中死亡。 There is great pleasure in watching wildlife in natural or near-natural environments, and tourism can add to the income of countries. The animals are still resources - but in a very different form. 在大自然当中或在接近于大自然的环境当中，欣赏野生动植物，真是一大赏心乐事，况且这种旅游观光业也能为国家或地方增加收入。各种动物都依然是我们的资源--但却是一种不同形式的资源。 
历次重大的烟雾杀人事件 On the night of December 1, 1930, a dense fog moved over the Meuse Valley, in Belgium. Many factories in the valley poured smoke and fumes into the foggy air. This created a dark smog of smoke and fog combined. People in the valley began to cough and train for breath. The smog remained for four days. During that time, thousands of people became ill. The hospitals were filled with patients. Sixty people died. Most of them were older persons with heart and lung problems. Finally, a heavy rain washed away the smog. Scientists studied the causes of the disaster. They concluded that the illnesses and deaths were caused by chemicals in the smog. 在1930年12月1日夜，一场浓雾漂移到了比利时的默兹山谷地区。在这山谷中的许多工厂都把烟尘和各种有害的微粒排放到这一场大雾当中了，于是就形成了烟与雾结合在一起的一大片浓黑的烟雾。这一山谷里的人们开始咳嗽，呼吸紧张。这场烟雾在这山谷里足足延续了四天，在这四天里成千上万的人病倒了。各家医院里都挤满了病人。结果60人死亡。死者中绝大多数都是患有心脏病和肺病的老人。最后，是一场大雨把这场烟雾冲洗掉了。科学家倦研究了这场灾难之后得出结论说，这场烟雾中的有害化学物质导致了人伞兵生病和死亡。 The first reported event of this kind in the United States happened in Donora, a factory town in a valley near Pittsburgh. In 1948, a killer smog made half of the population sick, there were 17 deaths. Again, older people with lung or heart diseases were hit hardest. 据报导，在美国的第一起这类事件发生在靠近匹兹堡的多诺拉。多诺拉是一个城镇，那里全是工厂。在1948年，一场烟雾导致了该镇有壮大数人口生了病，17人死亡。这里也还是患有肺病或心脏病的老年人受害最重。 London, England, has always been known for its "black fogs." In the winter of 1952, a milky white fog rolled into the city. It soon turned into black smog as the smoke of the city poured into the air. It was so hard to see that people had to walk in front of the buses to guide them. In this way, the most serious air pollution disaster in history began. When it was over, more than 4,000 people had been killed by the thick black smog. 英国伦敦一向以其"黑雾"称著于世。在1952年冬季，一厚层奶白色的雾滚滚漂进伦敦的空气当中。这场雾浓得令人什么也看不见，以致人们不得不步行在公共汽车的前头引导着司机慢慢开车前进。就这样，开始了历史上最严重的一场空气污染所造成的灾难。灾难结束时有四千多人被这场浓黑的烟雾夺去了生命。 New York City has had several London-type smogs since 1950. Each time, there were from 100 to 400 deaths caused by the smog. Although these smogs were not as deadly as London's, New York City has the worst air pollution problem in the United States. 自从1950年以来，美国纽约市发生了数起类似伦敦型的烟雾杀人事件。每次都因为有毒烟雾导致了一百到四百人的死亡。虽然这些烟雾令人致死的程度没有伦敦烟雾那样厉害，但是纽约市的空气污染问题在全美国是最坏的，最严重的。 
在所有这一切烟雾杀人的事件当中，都是由于各大小工厂和各个家庭把他们炉火中的烟尘和微粒排放到空气中所造成的。这些化学微粒同雾中的极微小的水珠结合起来就形成了各种有害的物质，这些有害物质是那些呼吸这些被污染了的空气的人致病的原因。 Usually, such harmful fumes rise into the upper air and are blown away by the wind. But sometimes there is an unusual weather condition called a temperature inversion. A layer of cold air remains near the ground as smoke and fumes pour into it. This is covered by an upper layer of warm air that acts like a lid. It prevents the polluted cooler air from rising. The harmful fumes pile up and make people ill. The smog may be so thick that airports are closed and chains of collisions occur on the highways. 一般情况下，这些有害的微粒漂浮到空气的上层以后，会被风吹走。但有时会有一种被称作"温度逆增"的不平常的天气状态。当烟尘和微粒拜谢到空气中以后，有一层冷空气仍然在贴近地面。这层冷空气就阻挡了这些被污染的冷空气，使之不能上升的高空中。这些有害的微粒越聚越多，于是就使人生病了。这些烟专利号有时很浓以致各个机场被迫关闭，公路上发生了一串一串的汽车相撞的事件。 Another type of smog occurs in Los Angeles. Here the weather may be clear and sunny. But stinging eyes and dry coughs show that harmful chemicals fill the air. The smog is due to invisible gases, mostly from automobile exhaust. Because these chemicals are changed by the sun high up in the air, Los Angeles smog is called photochemical smog. It contains automobile exhaust fumes and nitrogen oxides changed by the sun's rays. Added to these are sulfur dioxide and other fumes from factories and oil refineries. Photochemical smog is found in many large cities all over the world. 在美国洛杉矶出现过另一种烟雾。这里天气晴朗阳光灿烂，但是人们感到眼睛刺痛，出现干咳嗽。这些症状表明空气中充满了有害的化学物质。这种烟雾是由看不见的无色气体所组成，这种气体主要是汽车尾气中的微粒和被阳光照射后起了化学变化的氮氧化物，此外还有从工厂和炼油厂排放出来的二氧化碳和其他的悬浮微粒。在全世界很多大城市中都发现有光化学烟雾。 Killer smogs don't happen very often, fortunately. But in many large cities, a combination of automobile exhaust fumes, home furnace smoke, and factory waste gases pours into the air. This may also happen in the suburbs, or out in the country, where large factories have been built. A number of harmful substances have been found in the air there. When these substances are breathed in day after day, the health of the population is affected. 幸好，这种烟雾杀人事件并不是经常发生的。但在许多大城市中，都把汽车尾气中的微粒、家庭火炉冒出来的烟尘及工厂的废气汇合在一起排放到空气中去了。这种做法也会出现在郊区或城市外围的农村，因为这些地方都盖起了大型的各类工厂。在这些的空气中发现有很多的有害化学物质，人们日复一日地呼吸了这些有害物质，身体健康就会大受影响。
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