1月GMAT阅读新题精简版-自然科学

bigpig

 

自然科学类：............................................................................................................ 2fficeffice" />

中国竹子（补充阅读）..................................................................................................... 2

物种起源--细菌bacteria.................................................................................................... 3

测树龄（KG+【类似原文】+补充阅读）.......................................................................... 3

人的肌肉（KG）.............................................................................................................. 5

星系起源.......................................................................................................................... 8

温室气体、海水和云（高频+考古+补充阅读）................................................................. 9

CO2和SO2.................................................................................................................... 10

三种细胞的不同功能...................................................................................................... 10

细胞和动物长相的关系（KG）....................................................................................... 10

动物的逻辑能力（KG）................................................................................................. 10

吸收污染物.................................................................................................................... 13

Biomarker....................................................................................................................... 13

bigpig

 

中国竹子（补充阅读）

V5：

Bamboo, China, 公元999年发现，120年开一次花。 于是大家研究它开花时间。

P2学者说开花规律是因为内在生物钟调节，因为不同的种类竹枝，原本开花时间不一样的，一直到同一地域后，开花长短就变得基本一致。这种内在生物钟由外面的光决定。光照时间的长短影响里面的化学物质的光化学反映（光合作用？那个单词是photochemical之类的）时间

P3但是有一个地方的竹子，blahblahblah ，在热带雨林地方seasonal pattern表现不明显,学者解释说因为light difference也不明显。

V6：（V 45）

第一段讲有这么一种竹子120年开次花，应该跟环境无关，因为没有观察到有符合这个时间周期的环境变化，而且它即使被移植到另一个半球也不受影响。

第三段说因为营养不良的竹子和高大威猛的竹子同时开花，那么造成开花的原因一定不是营养，而是竹子内部某种对温度敏感的化学物质随着积累或者减少。（此处复制前人）而在赤道附近的5度纬度内的竹子则很少观察到uniform的开花节奏。。可能因为那里每天与每个季节的温度变化太微弱。

有一题关于bamboo species哪一个文中没提到还是not true之类的

我选了有提到开头那种奇怪的拉丁的竹子名字的那一项。。因为题目问的是整个bamboo species该选项只讲到这种竹子。。大家可以参考。。

V7：（730）

竹子开花好像有一道题是问削弱的，一下哪个会对小P的观点进行削弱

我选的是竹子开花随着温度的变化周期而变化，狗狗里面说是竹子内部某种对温度敏感的化学物质随着积累或者减少，我读的时候是temperature insensitive,应该是温度不敏感才对，所以选择随着温度变化来削弱

好像还有主题题，应该是解释一种现象吧

其它补充阅读：（By pipilovelail）

http://en.wikipedia.org/wiki/Bamboo

http://www.completebamboo.com/bamboo_flower.html

物种起源--细菌bacteria

V3：（V 45）

科学家认为只要有地球的生态条件一定会产生其他物种，有科学家认为可能地球上就有其他物种。但是有人反驳说即使存在不同生物,可能一种生物也已经被另一种生物适者生存的eliminate了.

然后提出两种细菌,说他们虽然来自几百万年前相同的祖先,但都现存。

这里祖先有细节考题,问下面哪一种关于细菌的说法是对的,我选的是A, 细菌a 的 line of ancestor 和细菌b 的 line of ancestor 不是independent的。

有一个选项有点迷惑。说两种细菌不require same resource，这是文章中没有的。。而题目是according to

最后科学家又说,可能不同生物是存在的,只是他们没有直接与现在我们看到的生物竞争资源,要么是因为他们居住地点不同,要么是因为他们所需要的资源不同.这里也有题，划出了某句话问他的作用，我记得这是第二段，然后结构很清晰的，有furthermore之类的词可以理清结构,最后说现在的技术限制了发现其他生物....但其他生物在未来有可能发现.

科学家认为地球上存在其它物种——有人反驳（即使有，也适者生存消灭掉了——科学家反驳这些人，有2个细菌，他们来自共同的祖先，但都存在——最后科学家总结自己的观点。

测树龄（KG+【类似原文】+补充阅读）

V2：（700）

第三篇是树年龄的测试,是最长的一篇,有一屏半,

P1 讲科学家通过测试树的年轮来知道树的年纪和气候变化的历史,但是赤道附近的数年轮不明显所以不方便测试.科学家只能通过一种很麻烦的碳和氧的方法来测定.

P2 讲一个p什么的人发明了一种新方法,通过测试一种C化学玩意可以看到树的年轮知道树的年纪,这种方法比老方法省时的多(有考新老办法对比),最后说这种方法有两个缺陷,所以这种方法还没有普遍接受,一个缺陷是干旱时期可能影响到树上的C玩意,第二个是不能确定所有的热带树上都有这个C, 题目有问怎么样做这种方法才能普遍接受. 答案在第三段的前一两句.

以下是一篇非常接近原文的文章，大家要仔细看：（非常感谢 pipilovelail）

源网址：http://www.popularmechanics.co.za/content/news/singlepage.asp?key=138

Tropic trees tell an age-old story

You can tell how old a tree is simply by counting its rings, which reflect the changing seasons. However, things are less straightforward when it comes to tropical热带 trees, since there are no summers and winters to mark the passage of time. Now scientists have worked out a simple way to tell the age of trees from the tropics, according to Nature. 

  

Currently, factors such as the width of tree rings in temperate zones are used to provide a detailed record of climate conditions for the past 1 000 years or so. But only a few types of trees in the tropics have visible rings: the variances between wet and dry seasons are too slight to leave a distinguishable mark.

Until now, scientists have depended on measurements of oxygen and carbon isotypes to determine their age, but Pascale Poussart, a geochemist at Princeton University in New Jersey, and her colleagues, have shown that an apparently ringless Miliusa velutina tree from Thailand does have rings... they're just invisible.

Using X-ray beams focused on wood samples, the researchers looked at calcium, a mineral that trees take up during their main growing season. They revealed annual peaks dating back to 1909.

Although the results were in line with carbon isotope measurements, the calcium method is much quicker. "It took us just one afternoon in the synchrotron to produce the record," says Poussart. "The isotope record cost four months of lab time."

The team doesn't yet know whether seasonal calcium cycles are common, or if the feature is specific to just a few types of trees. And it is unclear whether periods of drought, or the modest and patchy dry seasons that feature in some areas of the tropics, will make the signal undecipherable.

In search of answers, Poussart will be working with scientists at the Smithsonian Tropical Research Institute's Center for Tropical Forest Science, who run long-term forest monitoring programmes in Africa, Asia and Latin America.

At the moment, much about tropical systems is a mystery, so anything that helps measure time will make an important contribution to the understanding of tropical forest dynamics.

考古：（by delan714）

请参阅以下网址：http://forum.chasedream.com/GMAT_Math/thread-431406-1-2.html

 

以下考古 By XYXB

V6

这篇最简单，文章长，三段，但读起来容易，题目也不隐讳。前人写的足够详细。

第一段：一般温带的树年轮都很明显，但是热带季节变化不明显，年轮看不清楚（too subtle），只能用氧氮同位素法测定法来测定树的年龄，和它生活的时代的气候情况。这种办法看来是麻烦。

第二段：这个时候一个人发明了X-ray测定泰国热带的一种树的办法，通过X光测里面calcium cycle，说树每年生长的时候里面的钙都有个peak,1906年的结果和同位素法的方法结果一致。这种办法能让四个月的测量时间缩短到一下午。

最后一段：这种方法是否useful还需进一步检验。一是是否可以推广到世界上所有的热带雨林，还是只适用于泰国那个地方的树。二是flood呀，drought呀这些会不会影响到测量的准确性。所以这人还要和全球的气象学家继续研究。

题目有一道，貌似选的是：如果赤道的很多树都可以用这种方法的话，什么什么的，大概是一个加强方面的题，还有一道是选关于这个方法哪个是对的，我选的是和碳氧方法结果一致说明了这种方法的准确性，还有一道这种方法最大的优点，我选的是省时间

问题：

有一题：问关于这个科学家题出的新方法何者正确

答案选C就是他的结果和原始方法得出的结果一致加强了此方法的正确性

2，有一题：问下列哪一个是undermine第一段所说"热带树林 is too subtle to 显示气候的迹象"

我选了"最近在泰国地区 发现了三种新型态的热带树林他们的年轮痕迹是用肉眼（naked 赤裸的eye）就可以看出来的"

补充阅读：（By pipilovelail）

Dendrochronology：http://en.wikipedia.org/wiki/Dendrochronology

主要讲的是 radiocarbon dating的事情：http://www.apologeticspress.org/articles/2019

粉色最后一段：http://waynesword.palomar.edu/treedate.htm

bigpig

 

人的肌肉（KG）

V2：（710）

Theory 1: muscles go into automated brake when lactic acid builds up after exhausting exercise, leading to fatigue疲劳，劳累

Theory Two: psychologists argue central nervous system controls the sense of extreme fatigue to keep body from collapse; psychologists say that theory 1 is right about lactic build up, however wrong in the "location".( location=Central nervous system)

 

以下考古 By XYXB

V2

第一段，1922年有个诺贝尔大牛有个理论，说肌肉释放的什么酸是自动刹车，让肌肉休息。第二段，1989年加拿大的哥们有小异议，是补充理论，1999，南非三个哥们有新发现（主要内容）。第二段论证南非哥们的理论内容和原理。

第三段，总结他们的观点，有他们对1922年理论的评价，部分对，但没有指出，肌肉组织其实不是客观事实，而是受大脑操控的主观情绪影响，这才作用的。

类似原文：By pipilovelail

注意highlight的部分

Interestingly — or unnervingly, depending on how you look at it —  some researchers are uncovering evidence that Stanovnik’s rule of  thumb might be right. A spate of recent studies has contributed to  growing support for the notion that the origins and controls of  fatigue lie partly, if not mostly, within the brain and the central  nervous system. The new research puts fresh weight to the hoary  coaching cliché: you only think you’re tired.From the time of Hippocrates, the limits of human exertion were  thought to reside in the muscles themselves, a hypothesis that was  established in 1922 with the Nobel Prize-winning work of Dr. A.V.  Hill. The theory went like this: working muscles, pushed to their  limit, accumulated lactic acid. When concentrations of lactic acid  reached a certain level, so the argument went, the muscles could no  longer function. Muscles contained an ‘‘automatic brake,’’  Hill wrote, ‘‘carefully adjusted by nature.’’Researchers, however, have long noted a link between neurological  disorders and athletic potential. In the late 1800’s, the pioneering  French doctor Philippe Tissié observed that phobias and epilepsy  could be beneficial for athletic training. A few decades later, the  German surgeon August Bier measured the spontaneous long jump of a  mentally disturbed patient, noting that it compared favorably to the  existing world record. These types of exertions seemed to defy the  notion of built-in muscular limits and, Bier noted, were made  possible by ‘‘powerful mental stimuli and the simultaneous  elimination of inhibitions.’’Questions about the muscle-centered model came up again in 1989 when  Canadian researchers published the results of an experiment called  Operation Everest II, in which athletes did heavy exercise in  altitude chambers. The athletes reached exhaustion despite the fact  that their lactic-acid concentrations remained comfortably low.  Fatigue, it seemed, might be caused by something else.In 1999, three physiologists from the University of Cape Town Medical  School in South Africa took the next step. They worked a group of  cyclists to exhaustion during a 62-mile laboratory ride and measured,  via electrodes, the percentage of leg muscles they were using at the  fatigue limit. If standard theories were true, they reasoned, the  body should recruit more muscle fibers as it approached exhaustion —  a natural compensation for tired, weakening muscles.Instead, the researchers observed the opposite result. As the riders  approached complete fatigue, the percentage of active muscle fibers  decreased, until they were using only about 30 percent. Even as the  athletes felt they were giving their all, the reality was that more  of their muscles were at rest. Was the brain purposely holding back  the body?‘‘It was as if the brain was playing a trick on the body, to save  it,’’ says Timothy Noakes, head of the Cape Town group.  ‘‘Which makes a lot of sense, if you think about it. In fatigue,  it only feels like we’re going to die. The actual physiological  risks that fatigue represents are essentially trivial.’’From this, Noakes and his colleagues concluded that A.V. Hill had  been right about the automatic brake, but wrong about its location.  They postulated the existence of what they called a central governor:  a neural system that monitors carbohydrate stores, the levels of  glucose and oxygen in the blood, the rates of heat gain and loss, and  work rates. The governor’s job is to hold our bodies safely back  from the brink of collapse by creating painful sensations that we  interpret as unendurable muscle fatigue.Fatigue, the researchers argue, is less an objective event than a  subjective emotion — the brain’s clever, self-interested attempt  to scare you into stopping. The way past fatigue, then, is to return  the favor: to fool the brain by lying to it, distracting it or even  provoking it. (That said, mental gamesmanship can never overcome a  basic lack of fitness. As Noakes says, the body always holds veto  power.)‘‘Athletes and coaches already do a lot of this  instinctively,’’ Noakes says. ‘‘What is a coach, after all,  but a technique for overcoming the governor?’’The governor theory is far from conclusive, but some scientists are  focusing on a walnut-size area in the front portion of the brain  called the anterior cingulate cortex. This has been linked to a host  of core functions, including handling pain, creating emotion and  playing a key role in what’s known loosely as willpower. Sir Francis  Crick, the co-discoverer of DNA, thought the anterior cingulate  cortex to be the seat of the soul. In the sports world, perhaps no  soul relies on it more than Jure Robic’s.Some people ‘‘have the ability to reprocess the pain signal,’’  says Daniel Galper, a senior researcher in the psychiatry department  at the University of Texas Southwestern Medical Center at Dallas.  ‘‘It’s not that they don’t feel the pain; they just shift  their brain dynamics and alter their perception of reality so the  pain matters less. It’s basically a purposeful hallucination.’’Noakes and his colleagues speculate that the central governor theory  holds the potential to explain not just feats of stamina but also  their opposite: chronic fatigue syndrome (a malfunctioning,  overactive governor, in this view). Moreover, the governor theory  makes evolutionary sense. Animals whose brains safeguarded an  emergency stash of physical reserves might well have survived at a  higher rate than animals that could drain their fuel tanks at will.The theory would also seem to explain a sports landscape in which  ultra-endurance events have gone from being considered medically  hazardous to something perilously close to routine. The Ironman  triathlon in Hawaii — a 2.4-mile swim, 112-mile bike ride and  marathon-length run — was the ne plus ultra in endurance in the  1980’s, but has now been topped by the Ultra man, which is more than  twice as long. Once obscure, the genre known as adventure racing,  which includes 500-plus-mile wilderness races like Primal Quest, has  grown to more than 400 events each year. Ultramarathoners, defined as  those who participate in running events exceeding the official  marathon distance of 26.2 miles, now number some 15,000 in the United  States alone. The underlying physics have not changed, but rather our  sense of possibility. Athletic culture, like Robic, has discovered a  way to tweak its collective governor.

星系起源

V2：（710）

第一段，关于星系disk和elliptical（后面都用中文了）的形成，一直有一种普遍接受的观点。就是碟是spinning的形成的，而椭圆不是。但是有个残留问题一直没有解决，具体忘记了（无所谓，不考）。

第二段，现在，越来越多的天文学家开始支持另一种观点。就是这两种都是有spinning的形成的。椭圆的其实不是第一代的spining直接形成，而是他们碰撞的产生的啥啥啥形成的。-- 然后，文中给出了2给supportive -- (1)是一种推理（deduction),说他们距离很近，还有什么尾巴什么的，由于重力互相吸引，所以会碰collision (2)某人在某杂志（art of ...)上发表的一组照片，里面有什么tail啊什么的，说距离近了以后什么的就distorted了  ---(有一题，把这一段整个highlight了，吓到我了）

第三段，最近，又有计算机模拟(此处有hightlight,问是如何支持第二段的说法的)的结果支持了上一段的说法。具体不记得了。第三段提出电脑simulation结果不支持collision的假说，但是又部分支持了第二段的一些东西。有一个题问了第三段支持第二段的什么？（两个人

记忆的内容不太一样）

温室气体、海水和云（高频+考古+补充阅读）

V1：

P1 将什么导致大气变暖，简单，略看就行，没题。

P2 说有人提出建议用一种方法cool the planet，通过把什么seawater 什么（M打头的单词）送到太空增加云量。而这种云能反射太阳能量。这段后部分将这种方法的原理。

P3 讲怀疑论者提出反对意见，说这种方法可能引起什么不好的后果。最后一句话说提出建议的人回复假如这种方法不好用的话可以立即终止。

1）考了一个主题题

2）一个假设题，说建议这种方法的人基于什么假设。我选的是终止这项计划后不会有其他影响，好像是E（比较有把握）

3）还有一个细节题，说那个云层对大气变暖有什么影响。我选的是云层会在太阳能量到达地面之前吸收掉一部分（好像是迷惑选项，文中说的是反射，大家慎选）

V10：（V40）

第一段：最近二氧化碳的排放量远远超过预期，导致气温上升很快。因为问题严重，所以需要找到解决的办法。

第二段：科学家提出可以，增大反射阳光来阻止气温上升。而增大阳光发射的办法是增大表面光滑而且更白的云，这种云比普通的云发射能力强。增大这种云的办法是将海水雾化后洒入空中，空中的盐颗粒导致这种云的形成。

第三段：有人反对这个办法，原因有两条：一是会导致局部地区冷的时候更冷，热的时候更热；二是这种云比普通云相比，降水量明显减少。但是科学家们考虑到气温上升太快，认为这个方法还是利大于弊的。（注意，有考题问不白的云的特点是什么，我选择的是更容易产生降雨）

 

V8：“甲烷与全球变暖”

有考到“甲烷与全球变暖”的那篇。在NoY同学的寂静汇总当中，这篇与“岩石与气温突降”和“通过喷海水应对气候变暖”等三篇文章似乎混合成一篇了（个人观点，供参考）。我考到的是甲烷这篇，具体内容大概是

P1：甲烷(methane)是一种温室气体，会导致气候变暖。燃烧石油等方法会产生甲烷。

P2：Surprising，植物也会产生甲烷。举了个例子，科学家发现热带雨林上空有大量甲烷。该地区其他因素不可能产生这么大量的甲烷。

P3：这个发现有助于解释历史上的气候变迁与冰期的关系。原有理论认为是海底的甲烷突然大量释放而导致气候变暖。事实上，海床在4万年内都是稳定的（所以不可能突然释放甲烷）。合理的解释是，冰期的后期，植物大量生长，排放大量甲烷，这导致了气候上升，又导致了冰的融化，结束了冰期。

P4：虽然植物排放甲烷，但是他可以通过吸收二氧化碳等给气候带来正面的影响。所以不应该通过减少植物，而应该通过减少石油消耗来减少甲烷排放。

题目：1）第一段作用是什么；2）全文的主题是什么等等。

bigpig

 

CO2和SO2

V1：

第四篇是讲CO2和SO2的，这篇我没在狗狗里看到过，因为后来时间紧，就没太细看，大致是说：第一段说shipment散发SO2进入云层，使得气候变冷，第二段说，但是同时也散发CO2 使得气候变热，文章不长，题目有一道好像是问飞机和shipment之间散发的气体的比较（有点记不太清了）

三种细胞的不同功能

V1：

一篇讲述引起生物多样性的原因，开篇说犀牛啊之类的生物为什么成为犀牛，是因为细胞啊生物学的原因，之后详述了某学者及其团队的研究，他们发现有三种不同的细胞，各自有不同的功能，云云。详细的记不清了，请关注三种细胞各自的功能，有考题。

犀牛那个确实挺长，但是主要在后面两段，讲三种物质各有什么功能，定位比较容易，只要找到关键名词，其出现前后就有答案

（不知与上一篇是否为同一篇，有待考证）

细胞和动物长相的关系（KG）

V1：

第三篇讲的是细胞和动物长相的关系

P1：说为嘛犀牛长得像犀牛，而其他动物长得像其他动物呢？某个科学家在它书里做了个研究

p2:貌似是以前一个老的解释和现在解释的说明。、

p3:解释这个细胞在动物体内怎么影响外表~（有考点）

p4:继续解释

动物的逻辑能力（KG）

V1：（700）

还有一篇讲用一个动物作实验证明它们是不是有logic thinking 的能力

P2讲第一个实验。。。证明那个动物是有logical thinking 的能力地

P3讲了另一个试验。。。。再次证明那个动物是有 logical thinking的能力的 （慎用，俺verbal只有33）

以下考古 By XYXB

V8

乌鸦的逻辑思维能力.文章长,一定要小心.

开始讲科学家通过试验,发现乌鸦能够通过一系列复杂的行为(这部分内容很复杂,但是对于做题根本没有用,总之知道乌鸦这个行为表明了它能够逻辑思考就行)来获取一个精心设计放置的肉类.这个表明了他们用逻辑思维能力.

第二段就讲很多动物在试验中也可以一步一步的来获取复杂放置的食物.但是他们都是通过不断试错(这里有一道题)和研究人员在这个过程中每一步的食物鼓励做到 的,这个并不能说明这些小动物有逻辑思维能力.当然,有一种针对乌鸦试验的反驳观点认为乌鸦是在那个复杂行为中每一步发现肉更近了来获得精神激励,(这里 有道细节题,为反驳的观点是什么)不说明他们能逻辑思考.作者反驳了这种观点,提出一个有点复杂的理由.(总之知道作者不赞同就行了)

解 释:这里的意思是,因为乌鸦在那个复杂的行为中,每做一步就会发现肉离它更近了一点,所以受到了精神上面的鼓励,所以才会这么一步一步做下去.如果这个解 释成立的话,那么乌鸦就和那些在实验室中被研究人员一步一步用食物鼓励的小动物的行为没有差别了.那么这就说明了乌鸦没有逻辑思维能力,只是一种觅食本能 的反应. 这种解释就被用来反驳文章第一段中研究人员认为乌鸦有逻辑思维能力的推论.作者认为这个解释是不合理的,提出了一堆比较复杂的理由,认为这个反驳是不成立 的.

第三段,后来研究人员又做了一个类似第一段的试验,发现乌鸦并不具备逻辑思维能力.因此,文章的结论是乌鸦是否具备逻辑思维能力还不确定.

这篇阅读在11月的JJ上面有一篇参考的英文报道,非常有用,介绍的就是这个复杂的试验.看那篇报道对于理解这个试验很有帮助.但是一定要注意.JJ上面那篇参考文章的观点是乌鸦有逻辑思维能力,这篇考试文章的观点是乌鸦有没有逻辑思维能力还不确定.

其 他细节题都在上面我提示了,有一个推理题要注意:讲猴子怎样的行为才能说明它有逻辑思维能力.这个需要理解全文才能作.原来没有见过这个题型,所以记忆深 刻.我选的E.就是猴子通过一系列复杂的行为来获取水果.比较确定.其他选项很迷惑,但是仔细分析都是文章中用来说明乌鸦没有逻辑思维能力的理由,所以不 能证明猴子有逻辑思维能力.

附文章：

Clever ravenproves that it's no birdbrain

Logic andpuzzle-solving come naturally to highly intelligent scavenger, claim biologists

by Robin McKie,science editor

guardian.co.uk,Sunday April 29 2007 00.13 BST

TheObserver, Sunday April 29 2007

Article history

Scientists have revealed an unexpected candidate for the title of the world's second smartest creature - the raven. According to a pair of researchers, a bird brain is no longer a sign of stupidity; indeed, it could be a sign of surprising intelligence.

In the latest issue of Scientific American, Bernd Heinrich and Thomas Bugnyar - scientists based at Vermont University in Canada and St Andrews University in Scotland, respectively - reveal a series of experiments that provides startling backing for the idea that ravens are the brain boxes of the natural world. 'These birds use logic to solve problems and some of their abilities even surpass those of the great apes,' they say.

One startling experiment they outline involved ravens who were allowed to sit on perches from which pieces of meat dangled from string. To get a treat, a raven had to perform a complex series of actions: pull up some of the string, place a loop on the perch and hold it with a claw, then pull up another section of string and hold that loop on the perch. By repeating this process half a dozen times, a raven could reach the end of the string and get the meat.

'Some animals can be taught how to get food this way,' Heinrich said. 'However, I found ravens could perform this complex sequence of actions straight away. I was extremely surprised the first time I saw one of them do this. These birds have never seen string before or encountered meat hanging this way, yet they worked out exactly what they needed to do to get a treat.'

Many animals, birds and insects are capable of carrying out complex actions: nest-building, for example. However, such creatures are programmed genetically to undertake the different steps involved in such behaviour. Little intelligence is involved. By contrast, ravens have demonstrated that they can work out complex sets of actions, involving no tests or trial and error. This implies that they use logic. 'The birds acted as if they knew what they were doing,' the two researchers say in Scientific American. 'Ravens have the ability to test actions in their minds. That capacity is probably lacking, or present only to a limited extent, in most animals.'

Other experiments by biologists have shown that ravens often let other animals do work for them. In the wild, they have been known to make calls that bring wolves and foxes to dead animals so that these large carnivores can break the carcass apart, making meat accessible to the birds. Birds related to the raven also show surprising intelligence. The New Caledonian crow has been shown to fashion tools of leaves and to use them to extract grubs from crevices in trees, for example.

Scientists such as Heinrich and Bugnyar believe that ravens evolved their surprisingly high intelligence because of their complex social lives and scavenging lifestyles.

The birds have to be able to assess very quickly how close to a wolf or fox they can get when one is eating a dead animal: they need to get close enough to get food, but not be attacked themselves. However, Heinrich cautioned against stating unequivocally that the raven is the cleverest animal on Earth after humans. 'It is up there with the great apes and dolphins,' he said, 'but I think it is very difficult to say which is cleverer. There are different types of intelligence. I am good at biology but hopeless using computers, for example. Nevertheless, it is now clear the raven is one of the very smartest creatures we know about.'

吸收污染物

V1：

最后一个是说Tc 什么的， 就是一种物质可以吸收空气中的污染物。第二段说怎么吸收，吸收什么，最后一段说这物质还是有个问题。 题都不难。 但也可能是我掉进低分题库了，大家不一定能用上。

Biomarker

还有一篇新的，说的是biomarker。我虽对生物医学略有所知，但是了解不多，所以看这个link里面有解释到底什么是biomarker.

http://en.wikipedia.org/wiki/Biomarker

p1有科学家Federick S这个人在研究这个biomarker通过trace这个，可以知道到底哪些有害物质对人体造成哪些影响和病症。然后说这个研究的范围是limited,因为人身体的变化不光是由外界的pollutant造成的，更多的是饮食，生活习惯，还有其他原因。研究的时候这些原因都是不好排除的。

p2.说Federic终于找到了一个valid的实验方法。说他们找到一个小城市，这个城市里has severe air pollution.然后这个城里的工厂因为污染严重所以要关闭了。他们实验的对象就是那些工厂关闭前2年生出来的小孩子和关闭后生出来的小孩子。研究发现这个biomarker has a higher concentration in blood for those children born before the factory close than the ones born after. 然后说通过trace这些biomarker,有一个有毒物质缩写是BaP什么的，发现这个BaP在那些born before the factory close的孩子身上多。

文章不长也不难懂。然后第一题是weaken这个Federic的conclusion.我不记得了选项了。好像考了3个问题，实在记不清了，对不起同学们了。想起来我就来补充。

V2：（710）

某科学家跟他的研究小组，要研究biomarker和生病之间的关系。这一研究如果成功，将能够怎么怎么地。但是，现在对这个有争议controversial,原因是1.只有很少的biomarker确定跟病有关2很难排除别的因素，比如饮食什么的

但是，他们最近做了一个实验，号称很好。是选了一个small city,这个小地方有个什么工厂。最近关闭了。所以，可以前后对照（before-and-after comparison,注意这是考点）。工厂有pollutant。研究人员研究了在关厂之前2年出生的孩子，和关厂之后2年出生的孩子的健康状况。说，前面出生的有什么问题，后面的没有。furthermore,他们的blood concentration也不同。具体不记得。

问题有

(1)为什么这个实验有效，就是before-after comparison，当然选项是改写过的

(2)如何weaken结论。我选的是，政府出台了什么program，所以后来出生的孩子，他们的妈妈在怀孕阶段接受了什么。。。（其实是呼应了第一段讲这种方法的争议的原因）

(3)下面哪个选项是imply的。我在两个选项中纠结了很久，一个是讲人发病后可以看出biomarker,一个是biomarker可以prior to ailment

V3：

Biomaker那个很一页半。不难，前面大牛已经讲的很全面了，仔细看了一下，全部正确。。。。唉。。。我就这点用处。。。只记得activate有考点。

V4：

一个是BIOMARKER，与JJ的内容一致，补充两个题目：1、第二段XX学者的研究为什么使得BIOMARKER可以有用，因为他们的研究对象是？选项里面有：A. small city  B. children … 我选的B，因为原文说研究新生儿童受污染之害，可不受DIET和遗传的影响。

2、如果有以下发现，学者们对儿童的BIOMARKER研究的结论就削弱了？我选的是这些受害儿童的父母们体内的污染物含量，在生出孩子之前早就很高了。（其他选项不记得了）

lingshihong

many  thanks !!!!!!!!