2019年11月16日托福机经
机经（2）
TITLE:生态系统如何应对变化
1.
在继承过程中，某些物种在一个地区定居，其种群数量增加，而其他物种的种群数量下降甚至消失。
During succession some species colonize an area and their populations become more numerous, whereas populations of other species decline and even disappear.
2.
在土地上建立生产者，消费者和分解者社区之前，必须存在土壤：岩石颗粒，腐烂的有机物，空气，水和生物的复杂混合物，这些生物主要取决于气候，需要自然过程几百到几千年的历史。
Before a community of producers, consumers, and decomposers can become established on land, there must be soil: a complex mixture of rock particles, decaying organic matter, air, water, and living organisms that, depending mostly on the climate, takes natural processes several hundred to several thousand years to produce.
3.
这些早期演替植物物种生长在地面附近，可以在恶劣条件下迅速建立大量种群，并且寿命短。These early successional plant species grow close to the ground, can establish large populations quickly under harsh conditions, and have short lives.
4.
随着这些树种的生长并形成阴影，它们被可以容忍阴影的后期成功植物品种（主要是树木）所取代。
As these tree species grow and create shade, they are replaced by late-successional plant species (mostly trees) that can tolerate shade.
5.
水生候选物包括从严重污染中恢复的溪流以及已被筑坝或淹没的土地。
Aquatic candidates include streams recovering from heavy pollution and land that has been dammed or flooded.
TITLE:潮间带岩石社区
1.
海洋潮间带（最高潮位和最低潮位之间的区域）似乎是生物难以生存的地方。
Marine intertidal zones—those areas between the highest high-tide and lowest low-tide marks—appear to be difficult places for organisms to live.
2.
在多岩石的潮间带生物多样性和成功的原因之一是有大量可用的食物。
One reason for the great diversity and success of organisms in the rocky intertidal zone is the large quantity of food available.
3.
这里的生物成功的另一个原因是有大量的栖息地和生态位被占用。
Another reason for the success of organisms here is the large number of habitats and niches to be occupied.
4.
这些空间提供了躲藏处，安静的休息处，依恋地点，跳离点，裂缝，人们可以从那里窥视以获得惊喜的一餐，发起偷袭的立足点，隐蔽的交配角落以及遮蔽住处的黑暗环境。
These spaces provide hiding places, quiet places to rest, attachment sites, jumping-off spots, cracks from which to peer to obtain a surprise meal, footing from which to launch a sneak attack, secluded mating nooks, and darkness to shield a retreat.
5.
生活在高潮和低潮标记之间的生物所处的条件与低潮线之下的生物完全不同。Organisms living between the high-tide and low-tide marks experience very different conditions from those residing below the low-tide line.
机经（3）
TITLE:战后欧洲的阶级结构
1.
欧洲社会变得更加流动和更加民主。老阶级的障碍放松了，阶级区分变得更加模糊。European society became more mobile and more democratic. Old class barriers relaxed, and class distinctions became fuzzier.
2.
在19世纪和20世纪初，中产阶级的模式是独立的，个体经营的个体，他们拥有企业或从事过法律或医学等自由职业。
In the nineteenth and early twentieth centuries, the model for the middle class had been the independent, self-employed individual who owned a business or practiced a liberal profession such as law or medicine.
3.
他们务实而现实，主要关注效率和实际解决具体问题的方法。
Pragmatic and realistic, they were primarily concerned with efficiency and practical solutions to concrete problems.
4.
同时，工业工人阶级停止扩大，白领和服务业雇员的就业机会迅速增加。
Meanwhile, the industrial working class ceased to expand, and job opportunities for white-collar and service employees grew rapidly.
5.
例如，自1920年代以来，欧洲汽车工业在远远落后于美国之后迅速发展。
For example, the European automotive industry expanded phenomenally after lagging far behind the United States since the 1920s.
TITLE:为什么非禽类恐龙灭绝？
1.
来自不同来源的数据表明，白垩纪晚期（100到6500万年前）的气候比今天的气候温和，这是因为覆盖大陆的浅海。
Data from diverse sources indicate that the Late Cretaceous (100 to 65 million years ago) climate was milder than today’s because of shallow seas covering the continents.
2.
批评者还指出，在中生代期间，浅海航道已从大陆上撤退并在大陆上前进了很多次，那么为什么非禽类恐龙在与早期波动有关的气候变化中幸免于难？
Critics also point out that the shallow seaways had retreated from and advanced on the continents numerous times during the Mesozoic, so why did the nonavian dinosaurs survive the climatic changes associated with the earlier fluctuations but not with this one?
3.
熔岩淹没了印度的大部分地区，南大西洋和美国中西部的爆发性喷发向世界上大部分地区投掷了火山灰。
Lava flooded large areas of India, and explosive eruptions in the South Atlantic and the midwestern United States hurled ash over much of the globe.
4.
在代表白垩纪末尾的最后一层和代表新生代开始的第一层之间，通常有一层薄薄的粘土。Between the last layer representing the end of the Cretaceous and the first layer representing the start of the Cenozoic, there is often a thin bed of clay.
5.
通过测量在给定的时间内有多少这些陨石落到地球上，科学家可以估算将观察到的铱量沉积到边界粘土中可能要花费多长时间。
By measuring how many of these meteorites fall to Earth over a given period of time, scientists can estimate how long it might have taken to deposit the observed amount of iridium in the boundary clay.
机经（4）
TITLE:太平洋岛屿的动植物生活
1.
在太平洋及其周围的大洋洲岛上演化的生态系统既有很大的相似性，又有很大的多样性。There are both great similarities and considerable diversity in the ecosystems that evolved on the islands of Oceania in and around the Pacific Ocean.
2.
据估计，新几内亚有550多种鸟类，所罗门群岛有127种鸟类，斐济有54种，社会群岛有17种。
It is estimated that there were over 550 species of birds in New Guinea, 127 in the Solomon Islands, 54 in Fiji, and 17 in the Society Islands.
3.
结果，几乎在每个大小显着的岛上，其迎风面和背风面（远离风）之间都存在生态差异。As a result on nearly every island of significant size there is an ecological difference between its windward and leeward (away from the wind) sides.
4.
进化的另一个结果是，许多小环境拥有自己的特有（本地）物种，数量通常很少，没有被严重捕食，范围有限，因此容易受到破坏。
Another consequence of evolution was that many small environments boasted their own endemic (native) species, often small in number, unused to serious predation, limited in range, and therefore vulnerable to disruption.
5.
在没有哺乳动物和其他捕食者的情况下，也许最值得注意的是许多种类的不会飞的和地面嵌套的鸟类。
Perhaps most notable, in the absence of mammals and other predators, are the many species of flightless and ground-nesting birds.
TITLE:阿兹台克湖泊农业
1.
他们将湖泥、水生植物和腐烂的植被分层放置在结构芦苇的轻质骨架上，高出水面约1米，然后用快速生长的柳树固定平台周边。
They layered lake mud, aquatic plants, and rotting vegetation on a light skeleton of structural reeds to a height of about one meter above the water and then anchored the platform’s perimeter with rapidly growing willow trees.
2.
通过把作物带到水里而不是像传统灌溉那样把水带到作物里，它减少了劳动：根是通过毛细作用从下面灌溉的，在毛细作用下，水通过chinampa层的小空间被吸收。
By bringing crops to the water rather than water to the crops, as in traditional irrigation, it reduced labor: the roots were irrigated from below by capillary action, in which water was drawn up through the small spaces in the chinampa layers.
3.
在欧洲人每年收割一片庄稼两年的时间里，墨西哥人在他们通常温和的冬天的帮助下，可能收获八。
Over a two-year period in which Europeans reaped one crop per field, Mexicans, with the help of their typically mild winters, might harvest eight.
4.
阿兹特克人认为，在主湖特克斯科湖的中央附近有一个排水沟，因为他们无法解释一个封闭的水体，由许多河流和泉水供应，如何最终没有填满盆地。
The Aztecs believed that there was a drain near the middle of the main lake, Lake Texcoco, as they could not explain how an enclosed body of water, fed by numerous rivers and springs, did not eventually fill the basin.
5.
农民可能会用手灌溉整个田地，这也许可以解释为什么他们把田地建在运河之间。Farmers might irrigate entire fields by hand, which may explain why they built them narrow between the canals.
机经（5）
TITLE:动物的日长和繁殖时间
1.
有许多潜在的环境线索可以用来预测食物的到来并触发生殖器官的发育。
There are potentially many environmental cues that could be used to anticipate the arrival of food and trigger the development of the reproductive organs.
2.
14年来，他观察到大黄腿鸟的迁徙，这种鸟在加拿大繁殖，然后在秋天向南迁徙到巴塔哥尼亚，往返约16000英里。
For fourteen years he observed the migration of the greater yellowlegs, a bird that breeds in Canada and then migrates south to Patagonia in the autumn, a round-trip of some 16,000 miles.
3.
尽管加拿大冬季的气温低于零度，但这些鸟还是被人为的长时间繁殖所触发。
Despite the subzero temperatures of the Canadian winter, the birds were triggered to breed by the artificially long days.
4.
人工光周期的使用表明，尽管诸如突然的寒冷或温暖期之类的次要因素可能影响生殖发育的速度，但温度或食物供应本身并不能触发它。
The use of artificial photoperiods demonstrated that although secondary factors such as a sudden cold or a warm spell might affect the rate of reproductive development, temperature or food availability by itself could not trigger it.
5.
像绵羊和鹿这样的大型哺乳动物怀孕5到9个月不等。
Large mammals such as sheep and deer have a pregnancy that varies between five and nine months.
TITLE:人类对大型动物灭绝的责任
1.
这种证据的发现主要在美国西部，那里的猛犸象和其他大型食草动物的骨骼被挖掘出来，与用来杀死它们的武器有着不可否认的联系，这使得一些研究人员将北美更新世巨型动物灭绝归咎于古印度猎人。
The discovery of evidence like that found mainly in the American West, where bones of mammoths and other large herbivores have been excavated in undeniable association with the weapons used to kill them, leads some researchers to blame Paleo-Indian hunters for the extinction of North American Pleistocene megafauna.
2.
但这些动物是人类猎物的证据也不能证明人类猎杀了它们。
But evidence that these animals were human prey doesn’t also prove that humans hunted them to extinction.
3.
我们的观点是，地质记录提供了大量证据，证明自然过程足以解释在没有人类的情况下物种灭绝的原因。
Our point is that the geological record provides abundant evidence that natural processes are sufficient to account for species extinctions in the absence of humans.
4.
苏罗维尔和他的同事们对这个问题进行了长期的研究，并在大约180万年前的41个遗址中研究了人类对长鼻鲸的开发的全球考古记录。
Surovell and colleagues took a long-term view of the problem and examined the global archaeological record of human exploitation of proboscideans in 41 sites that span roughly the past 1.8 million years.
5.
后一次气候事件被称为年轻的旱季，标志着接近冰期的气候条件的恢复，并持续了1500年，从大约13000年到11500年前。
The latter climatic event, called the Younger Dryas, marked a return to near-glacial conditions and persisted for 1,500 years, from roughly 13,000 to 11,500 years ago.