新托福TPO17综合写作详细解析：鸟类数量减少的原因

阅读材料： In the past century, the steady growth of the human population and the corresponding increasing in agriculture and pesticide use have caused much harm to wildlife in the United States – birds in particular. Unfortunately for birds, these trends are likely to continue, with the result that the number of birds in the United States will necessarily decline. 在过去的⼀个世界，⼈类数量的增加以及随之⽽来的农业⽣产的发展和杀⾍剂的增加使得很多美国的野⽣动物受到了影响，⽽这种问题在鸟类上表现得更为明显。

更加不幸的是，由于⼈⼝数量、农业⽣产和杀⾍剂使⽤的趋势不会改变，美国的鸟类数量将会必然地随之下降。

First, as human populations and settlements continue to expand, birds’ natural habitats will continue to disappear. Forests, wetlands, and grasslands will give way to ever more homes, malls, and offices. As the traditional areas suitable for birds keep decreasing, so will the size of the birds’ populations that depend on those vanishing habitats. ⾸先，随着⼈⼝数量和居住⾯积的不断扩张，鸟类天然的栖息地持续地减少。

森林、湿地和草原都变成的住宅、商场和写字楼。

随着那些传统的适宜鸟类栖息的地⽅持续减少，失去赖以⽣存栖息地的鸟类，数量⾃然是减少的。

Second, agricultural activities must increase to keep pace with the growing human population. The growth of agriculture will also result in the further destruction of bird habitats as more and more wilderness areas are converted to agricultural use. As a result, bird populations in rural areas will continue to decline. 第⼆，为了能够满⾜增长的⼈⼝数量，农业活动也必须随之增加。

农业的增加的代价是进⼀步破坏鸟类的栖息地，越来越多的荒地变成了农业⽤地。

因⽽，鸟类在乡村的数量也随之持续减少。

Third, as human settlements expand and agriculture increases, the use of chemical pesticides will also increase. Pesticides are poisons designed to kill agricultural and home garden pests, such as insects, but inevitable, pesticides get into the water and into the food chain for birds where they can harm birds. Birds that eat the poisoned insects or drink contaminated water can die as a result, and even if pesticides do not kill birds outright, they can prevent them from reproducing successfully. So, pesticides have significantly contributed to declines in bird population, and because there will continue to be a need to control agricultural pests in the future, this decline will continue. 第三，随着⼈类居住地的扩展和农业的发展，化学农药的使⽤也增加了。

农药是⽤来杀死诸如昆⾍之类的⽣长在农⽥或者菜园的害⾍的有毒物质。

不可避免的是，这些农药会进⼊⽔系和⾷物链，进⽽伤害鸟类。

鸟类会吃被毒死的昆⾍或者喝污染了的⽔。

这样会导致鸟类的死亡，即便不会不会导致鸟类的⽴刻死亡，也会影响鸟类的繁殖。

所以，杀⾍剂会对鸟类的数量有⾮常严重的影响。

同时，因为即便是在将来，还是需要杀⾍剂来控制农业害⾍，所以，鸟类数量减少的趋势难以改变。

阅读部分需要提取的观点是： -Main point: 三个原因导致鸟类数量减少 - Sub point 1: ⼈类居住地的增加 - Sub point 2: 农业⽤地的增加 - Sub point 3: 杀⾍剂的使⽤ 听⼒材料： The passage claims that there will be fewer and fewer birds, but the arguments used to support this claim are unconvincing. 阅读⽂章声称鸟类的数量会越来越⼩，但是所使⽤的理由都是没有说服⼒的。

First, it’s true that urban growth has been bad for some types of birds, but urban development actually provides better and larger habitats for other types. So much so, that city and suburban dwellers often complain about increased bird populations – seagulls at landfills, pigeons on the streets and so on. Even birds like hawks and falcons can now be found in cities, where they prey on the increasing populations of pigeons and rodents. So, it’s not going to be a story of uniform decline of bird populations in the future. Some populations may shrink, but others will grow. ⾸先，确实城市的发展对于⼀些鸟类是不利的，但是城市的发展事实上也为其他的鸟类提供了更⼤更好的栖息地。

这样发展，城市的居民常常抱怨鸟类数量过多：堆填区的海鸥，⼤街上的鸽⼦，等等等等。

甚⾄那些不常出现在城市⾥的鸟类，⽐如鹰类也出现在城市，这是因为他们可以捕捉数量不断增加的鸽⼦和啮齿类动物。

所以，将来不会是所有鸟类的数量都在减少。

有⼀些的数量在减少，但是其他的在增加。

As for agriculture, it’s true that it too will increase in the future, but not in the way assumed by the reading passage. The truth is, in the United States, less and less land is being used for agriculture every year. Increases in agricultural production have resulted from and will continue to result from the introduction of new, more productive varieties of crops. These new crops produce more food per unit of land, and as a result, there’s no need to destroy wilderness areas. 对于农业来说，确实需求会越来越⼤，但是农业的增长并不是以阅读所提及的⽅式实现的。

在美国，实际上⽤在农业领域的⼟地每年都在减少。

农产品产量的增加是因为引进了新的、产量更⾼的农作物品种，⽽这种趋势将会持续。

这些新的农作物有更⾼的亩产量，因⽽，就没有必要破坏原有荒地⽤作农耕了。

And third, while it’s certainly true that traditional pesticides have been destructive to birds, it’s incorrect to project this history into the future. Now that, people are aware of the possible consequences of traditional pesticides, two changes have occurred. First, new and much less toxic pesticides have been developed, and that’s important. Second, and perhaps more importantly, there is a growing trend to develop more pest resistant crops, crops that are genetically designed to be unattractive to pests. Pest resistant crops greatly reduce the need for chemical pesticides, and best of all, pest resistant crops don’t harm birds at all. 第三，尽管传统的杀⾍剂的确会给鸟类带来损害，但是⽤过去推测未来的想法是站不住脚的。

现在⼈们已经意识到了传统杀⾍剂可能带来的危害，因⽽采取了两个措施。

⾸先，已经研究出了新型的、毒性更⼩的杀⾍剂，这是很重要的⼀个改变。

⽽第⼆点可能是更为重要的，就是现在正在研究能够抵抗⾍害的作物。

通过设计，使得农作物在基因上具有不吸引害⾍的能⼒。

抗⾍害作物能够极⼤的减少对化学杀⾍剂的需求。

更为重要的是，抗⾍害作物对鸟类是完全⽆害的。

听⼒部分需要提取的观点是： - Main point: 阅读部分的主张是站不住脚的 - Sub point 1: ⼈类的居住地的扩张不会导致所有鸟类数量的下降，有的会增加 - Sub point 2: 因为新品种作物的种植，农业⽤地会越来越少 - Sub point 3: 新型杀⾍剂的毒性变⼩，并且正在研制新型抗⾍害作物，将来杀⾍剂不会继续伤害鸟类。