剑桥雅思9阅读：Test1雅思阅读PASSAGE2真题+答案+解析

　   Passage2

　　Is There Anybody Out There?

　　外星有生命存在吗?

　　The Search for Extra-Terrestrial Intelligence

　　——搜寻外星文明计划

　　The question of whether we are alone in the universe has haunted humanity for centuries, bu we may now stand poised on the brink of the answer to that question, as we search for radio singnals from other intelligent civilisations. This search,often known by the acronym SETI (search for extra-terrestrial intelligence) , is a difficult one. Although groups around the world have been searching intermittently for three decades,it is only now that we have reached the level of technology where we can make a determined attempt to search all nearby stars for any sign of life.

　　人类是否是宇宙中存在的生命这个问题已经困扰我们几百年了，然而随着搜索来自其他智慧文明的无线电信号，现在我们或许离这个问题的答案已经不远了。这项也被称为SETI (search for extraterrestrial intelligence, 搜寻外星文明)的计划进行起来困难。虽然世界各地的团体已经断断续续地搜寻了三十多年，然而直到现在，我们所达到的技术水平才允许我们下定决心去尝试搜寻附近所有附近星球上的任何生命迹象。

　　A The primary reason for the search is basic curiosity - the same curiosity about the natural world that drives all pure science. We want to know whether we are alone in the Universe. We want to know whether life evolves naturally if given the right conditions, or whether there is something very special about the Earth to have fostered the variety of life forms that we see around us on the planet. The simple detection of a radio signal will besufficient to answer this most basic of all questions. In this sense, SETI is another cog in the machinery of pure science which is continually pushing out the horizon of our knowledge. However, there are other reasons for being interested in whether life exists elsewhere. For example, we have had civilisation on Earth for perhaps only a few thousand years, and the threats of nuclear war and pollution over the last few decades have told us that our survival may be tenuous. Will we last another two thousand years or will we wipe ourselves out? Since the lifetime of a planet like ours is several billion years, we can expect that, if other civilisations do survive in our galaxy, their ages will range from zero to several billion years.Thus any other civilisation that we hear from is likely to be far older, on average, than ourselves. The mere existence of such a civilisation will tell us that long-term survival is possible, and gives us some cause for optimism. It is even possible that the older civilisation may pass on the benefits of their experience in dealing with threats to survival such as nuclear war and global pollution, and other threats that we haven't yet discovered.

　　A 人类之所以搜索无线电信号，主要是出于一种基本的好奇心，正是这种对大自然的好奇心推动了所有纯科学的发展。我们想知道人类是否是宇宙中存在的生命。我们想知道在适宜的条件下，生命是否会自然形成。我们还想知道地球上是否存在某种特殊的物质，孕育了那些我们司空见惯的各种形式的生命体。只需监测一下无线电信号，这些最根本的问题就能够得到充分解答。从这种意义上来说，SETI 是纯科学系统发展的又一个重要推动力，而纯科学正不断拓宽着人类的知识范围。然而，人类之所以对其他地方是否存在生命这件事感兴趣，还有其他原因。比如，我们地球上的文明历史只有寥寥数千年，而过去几十年的核战争与污染的威胁告诉人类，我们的生命也许很脆弱。我们还能再延续两千年吗?还是将自我灭绝呢?既然像地球这样的星球拥有数十亿年的寿命，我们可以猜想，如果银河系中确实还有其他文明存在，那么它们的历史可能从零到数十亿年不等。因此，如果我们收到其他文明的信号，那它们的平均历史很有可能比人类历史长得多。只要这种文明存在，就说明生命是有可能长期存活的，同时也会带给我们一个保持乐观的理由。这些更古老的文明甚至有可能将其在应对生存威胁过程中积累下来的有益经验传授给我们，例如如何应对核战争与全球污染带来的威胁，以及如何应对其他我们尚未发现的潜在威胁。

　　B In discussing whether we are alone, most SETI scientists adopt two ground rules. First, UFOs (Unidentified Flying Objects) are generally ignored since most scientists don’t consider the evidence for them to be strong enough to bear serious consideration (although it is also important to keep an open mind in case any really convincing evidence emerges in the future). Second, we make a very conservative assumption that we are looking for a life form that is pretty well like us, since if it differs radically from us we may well not recognise it as a life form, quite apart from whether we are able to communicate with it. In other words, the life form we are looking for may well have two green heads and seven fingers, but it will nevertheless resemble us in that it should communicate with its fellows, be interested in the Universe, live on a planet orbiting a star like our Sun. And perhaps mostrestrictively, have a chemistry, like us, based on carbonand water.

　　B 在探讨我们是否是宇宙中存在的生命时，大多数 SETI 的科学家遵循两个基本原则。，UFOs (不明飞行物) 通常不在考虑范围内，因为大多数科学家认为UFO 的存在缺乏确凿的证据，不做慎重考虑(尽管保持开放的思想也很重要，同时以防将来会出现令人信服的(关于UFO的)证据)。第二，我们保守地假定我们正在搜寻的生命形式和人类相似，如果完全不同，那么我们可能不会把它看作是一种生命形式，更不用说能否与它进行交流了。换句话说，我们正在搜寻的生命形式也许会有两个绿色的脑袋和七根手指，但是它们和人类一样，能与同伴进行交流、对宇宙充满兴趣、生活在一个围绕恒星公转的星球上，就像地球绕着太阳转一样。也许更严格地说，它们和我们一样，由基本的化学物质碳和水构成。

　　C Even when we make these assumptions, our understanding of other life forms is still severely limited.We do not even know, for example, how many stars have planets, and we certain^ do not know how likely it is that life will arise naturally, given the right conditions. However, when we look at the 100 billion stars in our galaxy (the Milky Way), and 100 billion galaxies in the observable Universe, it seems inconceivable that at least one of these planets does not have a life form on it; in fact, the best educated guess we can make, using the little that we do know about the conditions for carbon-based life, leads us to estimate that perhaps one in 100,000 stars might have a life-bearing planet orbiting it. That means that our nearest neighbours are perhaps 100 light years away, which is almost next door in astronomical terms.

　　C 即使做出了这些假设，我们对其他生命形式的了解还是有限。比如，我们甚至不知道多少颗恒星有行星围绕，当然，我们也不知道在适宜的条件下，生命自然形成的可能性有多大。然而，当我们观测银河系中的 1000 亿颗恒星和可见宇宙中的1000亿个星系的时候，很难相信这些恒星中没有一个有生命存在。事实上，凭借我们仅有的一点对碳基生命的了解，我们所能做出的最有根据的推测是，或许每十万个恒星中的一个会有孕育着生命的行星围绕着它运转。这意味着我们最近的邻居离我们也许只有100 光年，从天文学角度来讲，这几乎就相当于和隔壁邻居的距离了。

　　D An alien civilisation could choose many different ways of sending information across the galaxy, but many of these either require too much energy, or else are severelyattenuated while traversing the vast distances across the galaxy. It turns out that, for a given amount of transmitted power, radio waves in the frequency range 1000 to 3000 MHz travel the greatest distance, and so all searches to date have concentrated on looking for radio waves in this frequency range. So far there have been a number of searches by various groups around the world, including Australian searches using the radio telescope at Parkes, New South Wales. Until now there have not been any detections from the few hundred stars which have been searched. The scale of the searches has been increaseddramatically since 1992, when the US Congress voted NASA $10 million per year for ten years to conduct a thorough search for extra-terrestrial life. Much of the money in this project is being spent on developing the special hardware needed to search many frequencies at once. The project has two parts. One part is a targeted search using the world's largest radio telescopes, the American-operated telescope in Arecibo, Puerto Rico and the French telescope in Nancy in France. This part of the project is searching the nearest 1000 likely stars with high sensitivity for signals in the frequency range 1000 to 3000 MHz. The other part of the project is an undirected search which is monitoring all of space with a lower sensitivity, using the smaller antennas of NASA's Deep Space Network.

　　D 外星文明可以选择多种不同的方式在银河系中发送信息，但是许多方式要么需要消耗过多的能量，要么在银河系中长距离传播时严重衰减。事实证明，在发射功率的情况下，频率在1000到3000兆赫 之间的无线电波传播的距离最远，所以到目前为止，我们主要在搜寻这个频率范围的无线电波。迄今为止，世界各地已经有许多不同的团体进行了搜寻，包括澳大利亚在新南威尔士的帕克斯用无线电天文望远镜进行的搜寻。直到现在，在已经搜寻过的几百个恒星中还没有任何发现。1992年，美国国会计划在以后的十年里每年为美国航空航天局投资1000万美元，用于对外星生命进行彻底搜寻。从那时起，搜寻的规模便开始大幅增加。项目中的资金用于开发可以同时搜索多个频率的特殊硬件 上。该项目分为两个部分，一部分是利用世界上的无线电天文望远镜进行有针对性的搜寻，分别通过位于波多黎各阿雷西沃港的、由美国操作的望远镜和位于法国南锡的、由法国操作的望远镜来完成。 这部分项目在距离最近的有可能接收到信号的1000颗活跃恒星中，对1000到3000兆赫的频率进行搜索。该项目的另一部分是利用美国航空航天局深空网的小天线进行不定向搜寻，监控所有不太活跃的宇宙空间。

　　E There is considerable debate over how we should react if we detect a signal from an alien civilisation. Everybody agrees that we should not reply immediately. Quite apart from the impracticality of sending a reply over such large distances at short notice, it raises a host of ethical questions that would have to be addressed by the global community before any reply could be sent. Would the human race face the culture shock if faced with 8 superior and much older civilisation? Luckily, there is no urgencyabout this. The stars being searched are hundreds of light years away, so it takes hundreds of years for their signal to reach us, and a further few hundred years for our reply to reach them. It's not important, then, if there's a delay of a few years, or decades, while the human race debates the question of whether to reply, and perhaps carefully drafts a reply.

　　E 如果我们真的发现了来自外星文明的信号，我们应该如何回应呢?这是一个备受争议的问题。所有人都认为我们不应该立即作出回应。且不说要马上向如此遥远的地方发出回应是多么不切实际，这还会引发一系列的民族问题，这些问题在回应被发出去之前必须由国际社会联合解决。如果面对一种更优越、更古老的文明，人类会不会面临着文化击呢?幸运的是，我们不需要立即作出回应，因为被搜寻的恒星离我们有数百光年之远，它们的信号到达我们这里需要数百年的时间，而我们作出的回应到达这些恒星又需要花上数百年。就这一点而言，当人类在争论是否要作出回应时，或者在精心起草回应内容的时候，再耽误个几年甚至几十年也没关系。

　　Question 14

　　答案: iv

　　关键词: assumptions, underlying

　　定位原文: B 段第 1 句“In discussing whether we are alone, most…”

　　解题思路: 这句明确表明 SETI 科学家在搜寻外星人时遵循两个基本原则。Ground 相当于题目中的 underlying, rules 相当于题目中的 assumptions，接下来的文字叙述两个原则分别是什么。考生从首句可以很明确地判断出正确答案是 iv。个别考生可能会看到 second 后面句子中的 assumption— 词，进而看到 a life form，就认为答案是 vi，这种选择显然是以偏概全的，是不正确的。段意必须能够涵盖一整段内容，而不是某个部分或者某句话的内容。因此本题答案是 iv。

　　Question 15

　　答案: vii

　　关键词: likelihood of, lives, other planets

　　定位原文: C 段第 3 句的后半句“… ; in fact, the best educated guess…”

　　解题思路: 这一段是无法仅仅从首句就判断答案的，需要读举例的内容，甚至读完整段，出题人不断用 guess, estimate, perhaps, might 这样的词来印证题干中的 likelihood 一词。

　　Question 16

　　答案：i

　　关键词：radio signals, from

　　定位原文：D 段第 1、2 句“An alien… It turns out…”

　　解题思路: 本段是文中正式提出搜寻外星生命的方法，radio waves 一词不断被重复。 Looking for 相当于题目中的 seeking，radio waves 相当于 radio signals，所有剩余 headings 中只有 i 和 ii 谈到了 radio signals，从逻辑上推测不可能是 ii，因为只有先搜寻外星信号，才可能谈到作回应的事情。故此题答案是 i。

　　Question 17

　　答案：ii

　　关键词：appropriate responses

　　定位原文：E 段第 1 句“There is considerate debate over…”

　　解题思路：本段首句明确提出如果收到了外星文明信号， 人类应该如何回应的问题。React 相当于题目中的 responses。而 how 暗指 appropriate。故答案是 ii。

　　Question 18

　　答案: several billion years

　　关键词：life expectancy, Earth

　　定位原文：A 段第 9 句“Since the lifetime of…”

　　解题思路: Earth 这个词出现在 A 段的第九行。顺着这个词再向下找到 lifetime, 显然这个词对应题目中的 life expectancy(寿命)一词，读完本句发现答案应该是 several billion years 。

　　Question 19

　　答案: radio waves

　　关键词：What kind of signals from other intelligent civilisations

　　定位原文：D 段第 1 句“An alien civilisation could choose…”

　　解题思路：本题定位与上一题相隔较远。但是如果已经先完成了 List of Headings 题目，就不难发现只有 D 段是在具体讲外星文明会选择哪种输送信息的方式。题目中问的是 SETI 科学家在搜寻从外星文明发来的哪一种信号，也就表明答案是个具体的信号形式，考生也就不难猜测答案是 radio waves。注意，此处问的是信号的形式，而不是电波频率，因此填 1000 或者 3000 MHz 是不正确的。

　　Question 20

　　答案：1000

　　关键词：How many, most powerful radio telescopes

　　定位原文：D 段倒数第 4 句“The project has two parts. One part is…”

　　解题思路：通过阅读题目，发现要寻找的是恒星的数量。只要定位数字 就能迅速找到本题的位置。于是，考生找到 1000 这个数字，并且能迅速排除下方的 1000 到 3000MHz。从 1000 这个数字向上看，考生可以看到 world’s largest radio telescopes 与题目中的 most powerful radio telescopes 是同义表达。

　　Question 21

　　答案：YES

　　关键词：Alien civilisations / the human race

　　定位原文：A 段最后一句“It is even possible that…” 这些更古老的文明甚至有可能将其在应对生存威胁过程中积累下来的有益经验传授给我们，例如如何应对核战争与全球污染带来的威胁，以及如何应对其他我们尚未发现的潜在威胁。

　　解题思路：根据题干关键字 alien civilisation 以及 List of Headings 题目留下的线索，最终会发现 A 段的最后一句话能够对应本题。be able to help 能够对应文中的 it is even possible, serious problems 对应文中的 threats。本题基本上属于同义词替换型的 YES 题目。

　　Question 22

　　答案：YES

　　关键词：SETI，resembles

　　定位原文：B 段第 3 句“Second, we make a very conservative assumption…” 第二，我们保守地假定我们正在搜寻的生命形式和人类相似。

　　解题思路: 本句的定位可以根据顺序原则推测，We 在这里指的就是 SETI 的科学家们， resemble humans 指的是 is pretty well like us。只要能顺利定位，就能够通过同义词转换解答。

　　Question 23

　　答案：NOT GIVEN

　　关键词：The Americans and Australians，Co-operated

　　定位原文：D 段第 3 句“...，including Australian searches using…”

　　解题思路：文章的 D 段虽然先提到了澳大利亚的搜寻工作，接着又提到了美国航空航天局负责的美国太空望远镜的搜索工作，但是并没有明确指出在这方面澳大利亚人和美国人有没有 cooperate，合作这个概念完全是出题人的杜撰，遇到这种情况，应该选择 NOT GIVEN。

　　Question 24

　　答案: NO

　　关键词: SETI scientists，have picked up

　　定位原文: D 段第 4 句“Until now there have …” 直到现在，在已经搜寻过的几百个恒星中还没有任何发现。

　　解题思路：此题定位处位于上一题定位词 Australian 的后方，比较好找。文中明确指出迄今为止，科

　　学家们还一无所获，而不是题目中所说的已经发现了信号。文中的 have not been 和题目中的 have picked up 相矛盾, 连时态都没有改变，是一道简单的同义词突型的 NO。

　　Question 25

　　答案：NOT GIVEN

　　关键词：NASA, Congress, criticism

　　定位原文：D 段第 5 句“The scale of the search…” 1992 年，美国国会计划在以后的十年里每年为美国航空航天局投资 1,000 万美元，用于对外星生命进行彻底的搜寻。从那时起，搜寻的规模便开始大幅增加。

　　解题思路：文中仅仅说国会通过议案给 NASA 拨款来对外星人进行彻底的搜寻，并未涉及这个项目有没有遭到某些议员批评一说。因此本题属于完全未提及型 NOT GIVEN。

　　Question 26

　　答案：NO

　　关键词：respond promptly

　　定位原文：E 段第 1、2 句“There is considerable debate over…” 如果我们真的发现了来自外星文明的信号，我们应该如何回应呢?这是一个备受争议的问题。所有人都认为我们不应该立即作出回应。

　　解题思路：文中这句话明确指出了对待外星人信号的态度，那就是不能立即回应，这与题目中提出的马上作出回应完全相反。Immediately 相当于 promptly。