“圣经”TPO是小伙伴们托福阅读备考中的必备资料，可是网上的参考资料还是供不应求。小编发现到手的资料中大多没有TPO33的阅读译文，所以前程百利小编为大家整理了TPO33阅读第三篇文章Extinction Episodes of the Past的译文，形式上不仅仅是翻译哦，为了大家在参考译文过程中能一举多得，小编找出了文章中那些对于托福值得积累的词汇并解析；一些在翻译中发现的长难句及分析；并一一附在相应段落下。希望能够对大家的托福备考产生更多帮助。
Extinction Episodes of the Past
过去的那些灭绝事件
【1】It was not until the Cambrian period, beginning about 600 million years ago, that a great proliferation of macroscopic species occurred on Earth and produced a fossil record that allows us to track the rise and fall of biodiversity. Since the Cambrian period, biodiversity has generally risen, but there have been some notable exceptions. Biodiversity collapsed dramatically during at least five periods because of mass extinctions around the globe. The five major mass extinctions receive most of the attention, but they are only one end of a spectrum of extinction events. Collectively, more species went extinct during smaller events that were less dramatic but more frequent. The best known of the five major extinction events, the one that saw the demise of the dinosaurs, is the Cretaceous-Tertiary extinction.
直到发生在约6亿年前的寒武纪时期,地球上的大型生物才开始大量繁殖并由此留下了用于追踪生物多样性高低的化石证据。自寒武纪以来,生物多样性普遍上升,但有一些明显的例外。由于发生在地球上的大规模生物灭绝，生物多样性至少在五个时期内急剧降低。这五大灭绝期得到了(研究人员)极大关注，但是它们仅仅是发生在连续性灭绝事件发生快结束的时候。总的来说,更多的物种灭绝发生在那些很小但是频繁的事件中。这五大时期中最著名的是恐龙灭绝的白垩纪—第三纪。
【2】Starting about 280 million years ago, reptiles were the dominant large animals in terrestrial environments. In popular language this was the era “when dinosaurs ruled Earth,” when a wide variety of reptile species occupying many ecological niches. However, no group or species can maintain its dominance indefinitely, and when, after over 200 million years, the age of dinosaurs came to a dramatic end about 65 million years ago, mammals began to flourish, evolving from relatively few types of small terrestrial animals into the myriad of diverse species, including bats and whales, that we know today. Paleontologists label this point in Earth’s history as the end of the Cretaceous period and the beginning of the Tertiary period, often abbreviated as the K-T boundary. This time was also marked by changes in many other types of organisms. Overall, about 38 percent of the families of marine animals were lost, with percentages much higher in some groups Ammonoid mollusks went from being very diverse and abundant to being extinct. An extremely abundant set of planktonic marine animals called foraminifera largely disappeared, although they rebounded later. Among plants, the K-T boundary saw a sharp but brief rise in the abundance of primitive vascular plants such as ferns, club mosses, horsetails, and conifers and other gymnosperms. The number of flowering plants (angiosperms) was reduced at this time, but they then began to increase dramatically.
大约在2.8亿年前,爬行动物是陆地上占主导地位的大型动物。那个时代，流行的语言应该是,这是“当恐龙统治地球,”各种爬行动物物种占据生态位的这一时期在流行语中被称作“恐龙统治”时代。但是，没有哪个群落或物种可以永远维持其主导地位，所以在过了约2亿多年后，也就是差不多在6500万年前，从种数相对稀少的陆生动物到包括今天我们知道的蝙蝠和鲸鱼在内的拥有无数种类的物种开始大量繁殖，“恐龙时代”猝不及防地走到了终点。古生物学家把这段地球历史标为白垩纪的结束和第三纪的开始,通常缩写为K-T Boundary。这段时期的特点还包括许多其他类型的生物发生着重大变化。总的来说，约38%的海洋动物家族消失了，一些菊石纲软体动物以更高的百分比从非常多元、丰富到濒临灭绝。名为“有孔虫”类的极其丰富的浮游海洋动物大量消失了，尽管他们后来又有反弹。看植物,K - T Boundary时期像是蕨类、苔藓类、楔叶类、松柏类等裸子植物这些原始维管植物发生了大幅度但短暂的上升。,被子植物数量在这时开始减少,但它们后来又开始急剧增加。
【3】What caused these changes? For many years scientists assumed that a cooling of the climate was responsible, with dinosaurs being particularly vulnerable because, like modern reptiles, they were ectothermic (dependent on environmental heat, or cold-blooded). It is now widely believed that at least some species of dinosaurs had a metabolic rate high enough for them to be endotherms (animals that maintain a relatively consistent body temperature by generating heat internally). Nevertheless, climatic explanations for the K-T extinction are not really challenged by the ideas that dinosaurs may have been endothermic, because even endotherms can be affected by a significant change in the climate.
是什么导致了这些变化呢?多年来科学家都认为气候变冷加之恐龙也因为像是现代一些爬行动物属于冷血动物而特别脆弱是说的通的。现在人们普遍认为,至少某些种类的恐龙会有足够高的代谢速率足够使他们体温恒定。然而,由于就算是恒温动物也会遭到气侯剧变的伤害，K-T灭绝的“气候解释”并没有受到这种观点的冲击。
【4】Explanations for the K-T extinction were revolutionized in 1980 when a group of physical scientists led by Luis Alvarez proposed that 65 million years ago Earth was stuck by a 10-kilometer-wide meteorite traveling at 90,000 kilometers per hour. They believed that this impact generated a thick cloud of dust that enveloped Earth, shutting out much of the incoming solar radiation and reducing plant photosynthesis to very low levels. Short-term effects might have included huge tidal waves and extensive fires. In other words, a series of events arising from a single cataclysmic event caused the massive extinctions. Initially, the meteorite theory was based on a single line of evidence. At locations around the globe, geologists had found an unusually high concentration of iridium in the layer of sedimentary rocks that was formed about 65 million years ago. Iridium is an element that is usually uncommon near Earth’s surface, but it is abundant in some meteorites. Therefore, Alvarez and his colleagues concluded that it was likely that the iridium in sedimentary rocks deposited at the K-T boundary had originated in a giant meteorite or asteroid. Most scientist came to accept the meteorite theory after evidence came to light that a circular formation, 180 kilometers in diameter in diameter and centered on the north coast of the Yucatan Peninsula, was created by a meteorite impact about 65 million years ago.
到了1980年，Luis Alvarez为首的物理学家们提出:6500万年前地球处在速度为90000公里/h的陨石撞击中，这彻底革新了关于K - T Boundary的解释。他们认为，这种撞击会产生包围地球的“浮尘厚层”，阻挡了大部分的太阳辐射，将植物光合作用减少到非常低的水平。短期效应可能包括巨大的潮汐和大范围火灾。换句话说,单一灾难性事件引发的一系列事件导致了大规模的物种灭绝。最初,陨石理论是基于单一事实的。在地球各个地方,地质学家们发现了大约6500万年前形成的异常高浓度的铱层沉积岩。铱元素在地表附近通常是罕见的,但它在某些陨石中很丰富。因此, Luis Alvarez和他的同事们得出的结论是：铱层沉积岩有可能是来源于大陨石或者小行星，在K - T Boundary时期沉积。在发现由约6500万年前一颗陨石的撞击形成的一个直径180公里、集中在尤卡坦半岛北海岸的形状时，大多数科学家接受了陨石理论。
词汇学习：
proliferation 增值，繁殖；扩散
例句：Brand proliferation is not a novelty, and it is profitable if you execute it well
品牌扩散并不新鲜，如果执行得好，它是会带来盈利的。
Concentration浓度；专心
例句：The challenge is to have the power of concentration to shut that out.
最大的挑战就是你要努力集中精神减少这些因素的干扰。
deposit n 存款v使沉积；寄存
例句：After I deposited the case in the left luggage office, she was gone with the $50 deposit.
在我把箱子存放在行李寄存处后，她就同50美元保证金一块儿不见了。
Revolutionize发动革命；彻底改革
例句：This sort of technology is set to revolutionize the nature of advertising. It's innovative and unique... and it's not something that's ever been possible before.
这种技术将会彻底变革广告的本质，它极具创新性和独特性，而这种技术之前从未出现过。
Abbreviate 缩写
例句：Use short and meaningful phrases, and abbreviate when necessary.
用短而有意义的短语，必要的时候用所写。
Label n标签v标注
label…as…为…贴上…的标签
例句：And so having a notion of good art, in the sense of art that does its job well, doesn't require you to pick out a few individuals and label their opinions as correct.
那么，即便承认有「好的艺术」--顺利实现其目的的艺术--这么一说的话，你也并不需要被迫选几个人出来并为他们的意见贴上「正确」的标签。
Sedimentary 沉淀的
例句：The deposits eventually become pressed under sedimentary weight into stone.
这些沉积物最终被沉淀性的重量压成岩石。
dominant有优势的；统治的，支配的
n dominance
例句：Fear once was the dominant driver in my life and I was dying inside because of it.
一旦恐惧成为了我生命中占有优势的掌控者，我的心灵将会因此而死去。
Responsible有责任的；可靠的
例句：We are responsible for what we do, no matter how we feel.
我们必须为我们做的事负责，无论我们怎么想。
Vulnerable 易受攻击的；有弱点的
例句：Not only network is vulnerable, any piece of software is.
不仅网络是脆弱的，任何一个软件都是脆弱的
Initially 首先
Collectively 共同地；全体地
Indefinitely 不确定地；无限期地
dramatically 戏剧地；引人注目地
Particularly独特地
长难句分析：
It was not until the Cambrian period, beginning about 600 million years ago, that a greatproliferation of macroscopic species occurred on Earth and produced a fossil record that allows us to track the rise and fall of biodiversity.
句子拆分：
主句：It was not until …that…
beginning about 600 million years ago 插入语，补充前面Cambrian period的说明
that allows us to track the rise and fall of biodiversity 定语从句，修饰“a fossil record”
However, no group or species can maintain its dominance indefinitely, and when, after over 200 million years, the age of dinosaurs came to a dramatic end about 65 million years ago, mammals began to flourish, evolving from relatively few types of small terrestrial animals into the myriad of diverse species, including bats and whales, that we know today.
and 前后两个分句，分句1 no group or species can maintain…
句子拆分：
分句2 mammals began to flourish
when, after over 200 million years, the age of dinosaurs came to a dramatic end about 65 million years age
嵌套插入语after over 200 million years的when引导的时间状语从句
evolving from relatively few types of small terrestrial animals into the myriad of diverse species, including bats and whales, that we know today.
嵌套插入语including bats and whales的动名词引导的状语从句
Among plants, the K-T boundary saw a sharp but brief rise in the abundance of primitivevascular plants such as ferns, club mosses, horsetails, and conifers and other gymnosperms.
可借鉴用法：…saw a rise/drop of …某段时期发生了什么变化
以上就是托福TPO阅读33第三篇文章的译文以及相关知识学习，希望能够帮助大家备考托福阅读。若您想了解托福考试更多相关信息请关注前程百利。
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