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GRE阅读高频机经原文及答案:地球冷暖周期

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gre的机经对我们的备考有很强的参考价值,为了方便大家,下面小编给大家带来GRE阅读高频机经原文及答案:地球冷暖周期,来看看吧!

GRE阅读高频机经原文及答案:地球冷暖周期

地球冷暖周期通过石头含铁量推定 新题

Recent studies of sediment in the North Atlantic’s deepwaters reveal possible cyclical patterns in the history of Earth’s climate. Therock fragments in these sediments are too large to have been transported thereby ocean currents; they must have reached their present locations by travelingin large icebergs that floated long distances from their point of origin beforemelting.

Geologist Gerard Bond noticed that some of the sedimentgrains were stained with ironoxide, evidence that they originated in localeswhere glaciers had overrun outcrops of red sandstone. Bond’s detailed analysisof deep-water sediment cores showed changes in the mix of sediment sources overtime: the proportion of these red-stained grains fluctuated back and forth fromlows of 5 percent to highs of about 17 percent, and these fluctuations occurredin a nearly regular 1,500-year cycle.

Bond hypothesized that the alternating cycles might beevidence of changes in ocean-water circulation and therefore in Earth’sclimate. He knew that the sources of the red-stained grains were generallycloser to the North Pole than were the places yielding a high proportion of“clean” grains. At certain times, apparently, more icebergs from the ArcticOcean in the far north were traveling south well into the North Atlantic beforemelting and shedding their sediment. Ocean waters are constantly moving, andwater temperature is both a cause and an effect of this movement. As watercools, it becomes denser and sinks to the ocean’s bottom. During some periods,the bottom layer of the world’s oceans comes from cold, dense water sinking inthe far North Atlantic. This causes the warm surface waters of the Gulf Streamto be pulled northward. Bond realized that during such periods, the influx ofthese warm surface waters into northern regions could cause a large proportionof the icebergs that bear red grains to melt before traveling very far into theNorth Atlantic. But sometimes the ocean’s dynamic changes, and waters from theGulf Stream do not travel northward in this way. During these periods, surfacewaters in the North Atlantic would generally be colder, permitting icebergsbearing red-stained grains to travel farther south in the North Atlantic beforemelting and depositing their sediment.

The onset of the so-called Little Ice Age (1300-1860),which followed the Medieval Warm Period of the eighth through tenth centuries,may represent the most recent time that the ocean’sdynamic changed in this way. If ongoing climate-history studies support Bond’shypothesis of 1,500-year cycles, scientists may establish a major natural rhythmin Earth’s temperatures that could then be extrapolated into the future.Because the midpoint of the Medieval Warm Period was about A.D. 850, anextension of Bond’s cycles would place the midpoint of the next warm intervalin the twenty-fourth century.

21.1. According to the passage, which of the following istrue of the rock fragments contained in the sediments studied by Bond?

A. The majority of them are composed of red sandstone.

B. They must have reached their present location over 1,500 years ago.

C. They were carried byicebergs to their present location.

D. Most of them were carried to their present location during a warm period inEarth’s climatic history.

E. They are unlikely to have been carried to their present location during theLittle Ice Age.

21.2. In the final paragraph of the passage (lines 27-33),the author is concerned primarily with

A. answering a question about Earth’s climatic history

B. pointing out a potential flaw in Bond’s hypothesis

C. suggesting a new focus for the study of ocean sediments

D. tracing the general history of Earth’s climate

E. discussing possibleimplications of Bond’s hypothesis

21.3. According to the passage, Bond hypothesized that whichof the following circumstances would allow red-stained sediment grains to reachmore southerly latitudes?

A. Warm waters being pulled northward from the GulfStream

B. Climatic conditions causing icebergs to melt relatively quickly

C. Icebergs containing a higher proportion of iron oxide than usual

D. The formation of more icebergs than usual in the far north

E. The presence of coldsurface waters in the North Atlantic

21.4. It can be inferred from the passage that in sedimentcores from the North Atlantic’s deep waters, the portions that correspond tothe Little Ice Age

A.. differ very little in composition from theportions that correspond to the Medieval Warm Period

B. fluctuate significantly in composition between the portions corresponding tothe 1300s and the portions corresponding to the 1700s

C. would be likely tocontain a proportion of red-stained grains closer to 17 percent than to 5percent

D. show a much higher proportion of red-stained grains in cores extracted fromthe far north of the North Atlantic than in cores extracted from further south

E. were formed in part as

答案:CEEC

再见,GRE阅读“马后炮”之文章类型

市面上经常有人将GRE文章分为现象解释型、问题解决型、新老观点对比型等类型,并大书特书。但如果考生将过多精力花在区别文章类型上面,其实是得不偿失的事情。

为什么这么说呢?因为这个分类本身就有问题。

比如一篇文章如果这么展开:

一个现象好奇怪呀!

传统的观点是:A可以解释。

但是现在有新的观点:B可以解释。

那这篇文章是属于现象解释型还是新老观点对比型?按照以上分类,这是一篇综合了现象解释和新老观点对比的文章,不能作非此即彼的论断。

再比如,新老观点对比型,这种分类暗示新老观点在文章论述逻辑里的地位是对等的,例如:关于一件事情以前和现在的人看法不一样。以前人们认为_X.但是现在人们认为YYY.

那么请问以下两篇文章能否被涵盖在内:

1. 关于一件事情以前人们的看法是_X。但是他们的看法有问题,正确的看法应该是YYY.

2. 关于一件事情以前人们的看法是_X。但是有一个新的看法是YYY.事实表明YYY这个看法很合理。

很明显这两篇文章和前面例子里的文章不一样,它们都是有作者观点态度的:1文里作者反驳前面观点,2文则是作者在新的看法后面引用事实表示支持。因此这两篇文章的重心都在作者观点态度上。有人可能会说,那再分细一点,加上反驳型文章和作者评价型文章。但就算类型分得更细更严谨,对我们考生来说也没什么实质性的好处,相反我们还要多记一些大名词并在做题时多花时间精力区别判断。原因是:分类更细后,我们也只有在读完一篇文章(而且是读懂了)才知道这是啥类型的文章啊!这完全是马后炮行为。

当然这种给文章分类的初衷可能是好的,也许是为了让我们更好地把握文章主线信息,更好地理解文章。但是最终的结果其实是有误导性的,它试图将文章固定在几种套路里,让我们产生一种套路在手,GRE阅读我有的感觉,而实际上呢它对我们如何读懂一篇文章(how)没有帮助,因为我们是读完了读懂了才知道这是啥类型的文章啊。而考生很多时候很难看出这种方法的问题:厉害的考生读懂了能辨别出文章类型,他会觉得这方法不坏,而不厉害的考生读完了没读懂分辨不出来,会觉得可能是自己方法掌握得不好。我觉得这可能也是某些马后炮行为一直流传在江湖中的原因之一。

结论是文章分类是没什么用的马后炮行为。关于文章“套路”“类型”,其实我们只需要知道出现现象后面极有可能解释,解释可能不只一个,关注解释间的关系;出现问题,文章后面可能会找解决方案,方案可能不只一种,关注方案间的关系;开始有引用观点,后面很有可能出现反驳(作者或别人);有这样一些简单的预期就可以了。我们应该把精力放在如何高效理解而不是找套路上面,至于如何高效理解,则不是一篇文章能说完的,有机会再另写文章阐述。

GRE长阅读要不要认真读取决于你的目标分数

应对GRE阅读考试,大家首先要关注的是节奏。 很多考生在准备GREVerbal的时候,想知道长阅读是否值得认真读。回答这个问题前,我们可以先看下GRE Verbal的题目构成,Verbal有两部分,具体如下:

从上表可以看出,第二个Verbal部分没有长阅读,所以这里和大家讨论的是第一部分的长阅读。大家可以看到,短阅读的字数只有120字,中篇阅读180个字,意味着60个字左右一道题。而长阅读450词只有四题,平均100多词解一题。这意味着长阅读是一个阅读和得分效率相对较低的题目。

考场上很多考生认真按顺序一题一题进行解答。在能力不充分时,这样做浪费大量时间,质量还没有保证,得不偿失。

下表给出的是几个典型分数对应的错题数量。大家都知道GRE是一个section adapted test,半自适应考试。Section2的难度取决于Section1的完成情况。

GRE错题数量及分数对应关系

  比如,表中第一个同学,第一部分只错了五道题,于是他的第二个部分就进入到了所谓的高分区间,难度系数达到了83分。他在第二部分错了九道题,因此他一共错了14道题,总分是一个非常好的分数160分。而我们通常认为高分档和低分档的准入门槛的错题数在第一部分应该是七道题。如果你错了七道题,是有可能进到高分档,也有可能进到中分档的。

  表里中间两行的同学成绩,第一部分都只错了七道题,但他们进入了难度不同的第二部分。第一个同学进到了高分档,仍然是83的难度系数,他第二个部分错了九道题,一共错了16道题。我们知道一共是40道题,错了16道题,其实错误率已经达到了40%,用百分制来说他应该是只得60分,但他最后的分数仍然是一个非常优秀的158分,因为他进到的是hard模式。下一个同学,第一个部分错了7个,第二个部分进到了中分档,难度系数66,他第二部分做得非常好,只错了5道题,一共只错了12道题,结果他的分数也是158分,这其实就是分数段的价值。

  第三个同学,第一个部分他错了9道题,第二个部分同样进到了中分档,我们知道中分档的区间第一个部分需要错的是7道题以上,14道题以内,他错了9个。第二个部分他错了14个,一共错了多达23道题,但是他的最后分数152,这是一个对于理工科同学申请优秀学校仍然够用的语文分数。

  根据分数分布发现,最后两个同学一个人错了12个,另一个人错了23个,这个人比前一个人多错了11道题,结果他们的分数差却只有差了6分,说明进到中分档以后的错题分数就不是特别敏感了。

  但高分档中的同学,section2错了16个,比进入中分档同学错的还多,但分数却一样,说明只要进入到了高分档,第二个部分其实想要冲击160之内分数是相当容易的。

  基于上述分析,针对到底要不要做长阅读我给大家的建议是,取决于你的GRE目标分数。如果你的目标分数是160分以上,则你必须认真完成长阅读。但如果你的目标分数是一个比较稳妥的150到160,我认为你是可以战略性搁置长阅读的。这个分数段的同学应该把更多时间花在擅长的题目上,而不是非要保证把所有题目做完。相比有同学在有限时间内稳妥做完题目,强求做完所有题目就无法不能保证准确率。

  GRE阅读词汇精选之贬低蔑视

  abase v.贬抑,使卑下

  belittle v.轻视,贬抑

  condescension n.自以为高人一等,贬低(别人)

  debase v.贬低,贬损

  decry v.责难,贬低(价值)

  demean v.贬抑,降低

  depreciate v.贬低,贬值

  derogate v.贬低,诽谤

  detractor v.贬低者

  disparage v.贬抑,· 轻蔑

  epithet n.(贬低人的)短语或形容词

  pejorative adj.带有轻蔑意义的,· 贬低的

  downplay v.贬低,· 低估

  underrate v.低估,估计过低,看轻

  contempt n.轻视,· 鄙视

  contemptible adj.令人轻视的

  disdain v.轻视、鄙视

  disdainful adj.鄙视的

  scorn n.v.轻蔑、瞧不· 起

  misprision n.轻视,· 蔑视

  despise vt.轻视

  slight v.\n. 轻蔑,怠慢 a.轻微的,纤细的

  flout v.蔑视,· 违抗

  defiance n.蔑视,挑衅

  sneer v.嘲笑,· 鄙视

  degrade v.降格,· 降级

  demote v.降级,· 降职

  relegate v.降级,· 贬谪

GRE阅读高频机经原文及答案:地球冷暖周期相关文章:

GRE阅读高频机经原文及答案:地球冷暖周期

gre的机经对我们的备考有很强的参考价值,为了方便大家,下面小编给大家带来GRE阅读高频机经原文及答案:地球冷暖周期,来看看吧!GRE阅读高频机经原文及答案:地球冷暖周期地球冷暖?
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