托福综合写作优秀作文练习题：海洋中的海獭

 　　下面是托福综合写作练手材料系列——《托福综合写作练手材料 海獭数量急剧减少的原因》。

　　托福综合写作阅读材料：

　　The sea otter¹ is a small mammal that livesin waters along the western coast of North America from California to Alaska.When some sea otter populations off the Alaskan coast started rapidly declininga few years ago, it caused much concern because sea otters² play an importantecological role in the coastal³ ecosystem⁴. Experts started investigating thecause of the decline and quickly realized that there were two possibleexplanations: environmental pollution or attacks by predators⁶. Initially⁷, thepollution hypothesis seemed the more likely of the two.

　　海獭是一种生活在北美西海岸从加州到阿拉斯加沿线的小型海洋哺乳动物。几年前，阿拉斯加海岸的海獭数量急剧减少。由于海獭对于维持海岸沿线生态平衡有非常重要的作用，所以其数量下降引起了广泛的关注。专家开始研究海獭数量下降的原因，并且很快发现了两个可能的原因，分别是环境污染和天敌捕食。最初，环境污染说看起来更为可信。

　　The first reason why pollution seemed themore likely cause was that there were known sources of it along the Alaskancoast, such as oil rings and other sources of industrial chemical pollution. Watersamples from the area revealed increased levels of chemicals that coulddecrease the otters’ resistance to life-threatening infections and thus couldindirectly cause their deaths.

　　为什么污染说更为可信呢?这是因为阿拉斯加海岸确实有污染源，比如石油带或者其他的工业污染物。该地的水样显示水中化学物的含量增加，其数量可以导致海獭对于一些致命感染丧失抵抗力，进而间接导致数量下降。

　　Second, other sea mammals such as seals andsea lions along the Alaskan coast were also declining; indicating that whateverhad endangered the otters was affecting other sea mammals as well. This factagain pointed⁸ to environmental pollution, since it usually affect the entire ecosystemrather than a single species. Only widely occurring predators, such as the orca(a large predatory whale), could have the same effect, but orcas prefer to huntmuch larger prey⁹, such as other whales.

　　第二，在阿拉斯加海域，包括海豹和海狮在内的其他海洋哺乳动物的数量也有所下降。这表明造成海獭数量下降的原因也对其他海洋哺乳动物造成了影响。原因再次指向了环境污染，这是因为环境污染问题常常不是仅仅影响某个特定物种，而是影响整个生态系统。除此之外，只有像逆戟鲸(一种大型肉食鲸)那种食性广泛的动物才能通过捕食呈现相同的效果。但是，逆戟鲸更喜欢捕食像鲸类这种的大型猎物。

　　Third, scientists believed that thepollution hypothesis could also explain the uneven¹⁰ pattern of otter decline: atsome Alaskan locations the otter populations declined greatly, while at othersthey remained stable. Some experts explained these observations by suggestingthat ocean currents or other environmental factors may have created unevenconcentrations of pollutants¹¹ along the coast.

　　第三，科学家认为污染说同时可以解释海獭数量变化的不均衡性。所谓不均衡性是指在阿拉斯加某些区域海獭数量下降明显，而在其他地方海獭的数量保持未定。一些专家指出这样的观察结果表明洋流和其他环境因素导致了海岸线上污染物的不均衡聚集。

　　托福综合写作阅读部分需要提取的观点是：

　　- Main point: 海獭数量下降的原因是环境污染

　　- Sub point 1:阿拉斯加海域确有污染源

　　- Sub point 2:除海獭外，还有其他哺乳动物的数量下降

　　- Sub point 3:不同区域海獭数量下降情况不同，可以解释为污染物聚集情况不同导致的。

　　托福综合写作听力观点：

　　Well, ongoing¹² investigations¹³ have revealedthat predation is the most likely cause of sea otter decline after all.

　　目前的研究表明天敌捕食是最可能导致海獭数量减少的原因。

　　First, the pollution theory is weakened bythe fact that no one can really find any Dead Sea otters washing off on Alaskanbeaches. That’s not what you would expect if infections caused by pollutionstarted killing¹⁴ a lot of otters. On the other hand, the fact that it’s so hardto find dead otters is consistent with the predator⁵ hypothesis. If an otter iskilled by a predator, it’s eaten immediately so it can’t wash up on shore.

　　首先，由于没有人发现有海獭尸体被冲上阿拉斯加海滩，所以污染理论捕食那么站得住脚的。如果污染造成的疾病感染导致了海獭数量的剧减，那么情况不该如此。而且，很少发现海獭尸体也恰恰说明了天敌捕食假说。捕食者杀死了海獭后，会很快地吃掉它，那么我们也就不会再岸上发现海獭尸体了。

　　Second, although orcas may prefer to huntwhales, whales have essentially¹⁵ disappeared from the area because of humanhunters. That means that orcas have had to change their diet to survive and sinceonly smaller sea mammals are now available, orcas have probably started huntingthose. So, it probably is the orcas that are causing the decline of all thesmaller sea mammals mentioned in the passage - the seals, the sea lions, andthe sea otters.

　　第二，尽管逆戟鲸喜欢捕食鲸类，但是鲸类的数量却由于人类的捕猎活动而剧烈减少。这意味着逆戟鲸不得不为了生存而更改捕食习惯。目前来看只有一些小型海洋哺乳动物还可以捕捉，逆戟鲸很可能开始以它们为食了。所以，很可能是逆戟鲸的捕食导致了文中提到的诸如海豹、海狮和海獭等小型哺乳动物的数量减少。

　　And third, the uneven pattern of otterdecline is better explained by the orca predation theory than by the pollutiontheory. What happens to otters seems to depend on whether the location where theylive is accessible to orcas or not. In those locations that orcas can accesseasily, the number of sea otters has declined greatly. However, because orcasare so large, they can’t access shallow or rocky locations. And shallow androcky locations are precisely¹⁶ the types of locations where sea otterpopulations have not declined.

　　第三，海獭数量变化的不均衡性恰好表明了逆戟鲸捕食理论比污染理论更合理。海獭数量的增减取决于它们生存的地方逆戟鲸是不是可以进入。在那些逆戟鲸很容易进入的海域，海獭的数量急剧减少。然而，因为逆戟鲸个头很大，所以他们不能进入那些过浅或者充满岩石的海域。而那些过浅和充满岩石的海域，恰恰是海獭数量保持稳定的地区。

　　托福综合写作听力笔记：

　　Main point: 天敌说更为可信

　　Sub point one: 没有发现海獭的尸体

　　Sub point two: 多种小型海洋哺乳动物的减少是因为逆戟鲸捕食

　　Sub point three: 逆戟鲸个头很大，有的海域不能进入，解释了为何数量变化不均衡

　　提示：在阅读部分出现的陌生的名词(包括专有名词)要记下来，因为听力出现的时候我们要根据读音判断出现位置和大致含义。

　　本篇范文可以借鉴的模板

　　The lecturer and the reading passagesuggest two competing theories, _______V.S.__________, to explain______________________.

　　The professor reasons that _____________ isnot caused by _______but rather by ______. In contrast, the reading passageattributes _______ to _____, citing evidence of ______________.

　　Furthermore, the lecturer argues that________ are likely factors in ________, because ________.

　　The reading passage, on the other hand,rules out this theory based on __________, and instead approves of the______theory as the only explanation for ______________.

　　Finally, according to the lecturer, ________________.However, the reading passage argues that _________ factors betterexplains_________.

　　托福综合写作范文(仅供参考)：

　　The lecturer and the reading passagesuggest two competing theories, the predation theory vs. the pollution theory,to explain why the sea otter population is in rapid decline.

　　The professor reasons that the absence of DeadSea otters washed up the coast suggests that their decline is not caused by seapollution but rather by sea predators who consume their bodies after killingthem. In contrast, the reading passage attributes the death of sea otters topollution, citing evidence of increased sources of ocean contaminants whichlead to greater vulnerability to infections.

　　Furthermore, the lecturer argues that orcasare likely factors in the disappearance¹⁷ of sea otters, because the scarcity¹⁸ ofwhales, their usual prey, has left them with no other choice but to start huntingsmaller mammals like the otters for food. The reading passage, on the otherhand, rules out this theory based on the orca’s prepaying habit, and insteadapproves of the pollution theory as the only explanation for the decline ofboth large and small sea mammals across the entire ecosystem.

　　Finally, according to the lecturer, theuneven pattern of sea otter decline corresponds to the distribution of theorcas; she argues that the fact that their population has declined most rapidlywhere orcas are most prevalent further validates¹⁹ the predation theory. However,the reading passage argues that chaneable environmental factors, which lead todifferent concentrations of pollutants, better explains the varying pattern ofsea otter decline.

1 otter   

n.水獭

参考例句：

• The economists say the competition otter to the brink of extinction.经济学家们说，竞争把海獭推到了灭绝的边缘。
• She collared my black wool coat with otter pelts.她把我的黑呢上衣镶上了水獭领。

2 otters   

n.（水）獭( otter的名词复数 )；獭皮

参考例句：

• An attempt is being made to entice otters back to the river. 人们正试图把水獭引诱回河里去。 来自《简明英汉词典》
• Otters are believed to have been on Earth for 90 million years. 水獭被认为存活在地球上已经9千多万年。 来自互联网

3 coastal   

adj.海岸的，沿海的，沿岸的

参考例句：

• The ocean waves are slowly eating away the coastal rocks.大海的波浪慢慢地侵蚀着岸边的岩石。
• This country will fortify the coastal areas.该国将加强沿海地区的防御。

4 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。

5 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

6 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

7 initially   

adv.最初，开始

参考例句：

• The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
• Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。

8 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

9 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

10 uneven   

adj.不平坦的，不规则的，不均匀的

参考例句：

• The sidewalk is very uneven—be careful where you walk.这人行道凹凸不平—走路时请小心。
• The country was noted for its uneven distribution of land resources.这个国家以土地资源分布不均匀出名。

11 pollutants   

污染物质（尤指工业废物）( pollutant的名词复数 )

参考例句：

• Pollutants are constantly being released into the atmosphere. 污染物质正在不断地被排放到大气中去。
• The 1987 Amendments limit 301(g) discharges to a few well-studied nonconventional pollutants. 1987年的修正案把第301条（g）的普通排放限制施加在一些认真研究过的几种非常规污染物上。 来自英汉非文学 - 环境法 - 环境法

12 ongoing   

adj.进行中的，前进的

参考例句：

• The problem is ongoing.这个问题尚未解决。
• The issues raised in the report relate directly to Age Concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。

13 investigations   

（正式的）调查( investigation的名词复数 )； 侦查； 科学研究； 学术研究

参考例句：

• His investigations were intensive and thorough but revealed nothing. 他进行了深入彻底的调查，但没有发现什么。
• He often sent them out to make investigations. 他常常派他们出去作调查。

14 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

15 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

16 precisely   

adv.恰好，正好，精确地，细致地

参考例句：

• It's precisely that sort of slick sales-talk that I mistrust.我不相信的正是那种油腔滑调的推销宣传。
• The man adjusted very precisely.那个人调得很准。

17 disappearance   

n.消失，消散，失踪

参考例句：

• He was hard put to it to explain her disappearance.他难以说明她为什么不见了。
• Her disappearance gave rise to the wildest rumours.她失踪一事引起了各种流言蜚语。

18 scarcity   

n.缺乏，不足，萧条

参考例句：

• The scarcity of skilled workers is worrying the government.熟练工人的缺乏困扰着政府。
• The scarcity of fruit was caused by the drought.水果供不应求是由于干旱造成的。

19 validates   

v.证实( validate的第三人称单数 )；确证；使生效；使有法律效力

参考例句：

• Other research validates that when it comes to chocolate, type does matter. 其他的研究也证实了不同种类的巧克力确实功效不同。 来自互联网
• Trouble shoots equipment, review and validates data and complete reports. 管理错误描述设备，审查并确认试验数据，完成试验报告。 来自互联网