经典例题485 Thus it happened that when the new factories that were springing up required labor，tens of thousands of homeless and hungry agri cultural workers，with their wives and children，were forced into the cities in search of work，and any work，under any condition，that would keep them alive.

　　结构分析:句子的框架是it happened that…。it做形式主语，that引导的从句做真正的主语。主语从句中，又有一个由when引导的时间状语从句，主句为tens of thousands of homeless and hungry agricultural workers…were forced…，时间状语从句中从句主语the new factories又带有一个定语从句that were springing up;that would keep them alive做work的定语从句。spring up意为“发生，出现，建立”。

　　参考译文 于是就出现了这样的情况:正当新办的工厂纷纷建立，需要劳动力的时候，成上万无家可归、饥肠辘辘的从事农业的劳动者携家带口，被迫溜入城市;他们要找活干，不管什么活儿，不讲什么条件，只要不使他们饿死就行。

　　经典例题486 As a result of two or three centuries of scientific investigation we have come to believe that Nature is understandable in the sense that when we ask her questions by way of appropriate observations and experiments，she will answer truly and reward us with discoveries that endure.

　　结构分析:句子的框架是…we have come to believe that…。that引导的从句做believe的宾语从句;此从句中有一个that从句作the sense的同位语从句;同位语从句中又套嵌一个由when引导的时间状语从句;此时间状语从句又套嵌一个定语从句that endure，修饰其先行词discoveries。by way of意为“经由，通过…方法”;reward sb.with意为“以…报答，酬劳”;endure此处应译为“持久，持续”，不要译为“忍受，容忍”。

　　参考译文 由于两三个世纪以来科学研究的结果，我们逐渐相信，如果运用合适的观察和实验方法向大自然探究问题，她会真心实意地给我们答复，并且以永垂不朽的发现来报答我们。从这个意义上来说，大自然是可以认识的。

　　经典例题487 These new observational capabilities would result in simply a mass of details were it not for the fact that theoretical understanding has reached the stage at which it is becoming possible to indicate the kind of measurements required for reliable weather forecasting.

　　结构分析:句子的框架是These new observational capabilities would result in simply a mass of details…。后面紧跟省略了if引导的虚拟条件句were it not for the fact that…，即if it were not for the fact that…;that从句作the fact的同位语从句。此从句中又套嵌一个定语从句，修饰其先行词the stage;required for reliable weather forecasting为过去分词短语修饰the kind of measurements。simply译为“只不过，仅仅”，不应译为“简单地”。

　　参考译文 理论上的认识已达到了这样的阶段———现在已能指出需要哪种测量方式才能可靠地预报天气，如果做不到这一点，那么上述这些新的观察能力只不过提供了一大堆细节而已。

　　经典例题488 The story of the discovery of what is now generally called the principle of Archimedes，namely that a solid body when immersed in a liquid loses a portion of its weight of the liquid it displaces，has many different versions，of which the following is one.

　　结构分析:句子的框架是The story…has many different versions…。what is now generally called the principle of Archimedes为名词性从句做介词of的宾语。namely that a solid body…作the principle of Archimedes的同位语;when immersed in a liquid是省略了主语的过去分词短语，句子补充完整为when the solid body is immersed in a liquid，修饰其主句a solid body loses a portion of its weight of the liquid…;it displaces是省略了关系代词that的定语从句修饰the liquid，it代指前面提到的the solid body;同时，of which the following is one又构成先行词versions的定语从句。displace意为“排（水）”;version不译为“版本”，此处指“根据个人观点的（对事件等的）说法，看法”;句尾的one代指a version。

　　参考译文 当固体浸没到液体中时，固体会失去它所排出的液体的那部分重量，这就是现在通常所谓的阿基米德原理。有关这一发现的故事有很多说法，下面的故事就是其中之一。

　　经典例题489 We assumed that there were forces of attraction between molecules which varied rapidly with the distance so that the attraction between molecules that were more than a few ten_millionths of a millimeter apart was very small but became considerable when the molecules approached more closely.

　　结构分析:句子的框架是We assumed that there were forces of attraction…。that引导宾语从句。此宾语从句中套嵌一个由which引导的定语从句修饰先行词forces of attraction;so that the attraction between molecules…是so that结构引导的结果状语从句;在此状语从句中，除主干结构the attraction…was very small but became considerable…，又有that were more than a few ten_ millionths of a millimeter apart做定语从句修饰先行词molecules和when the molecules approached more closely做状语从句，修饰…but became considerable。considerable译为“相当大（或多的）”。

　　参考译文 我们曾经假定，分子之间存在着引力，这种引力随着分子之间距离的不同而有显著的变化，因而，在间距为千万分之几毫米的分子之间的引力是很小的，但是分子靠得很近时，这种引力会变得相当大。

　　经典例题490This need is enshrined in the concept of sustainable development，which means that we must，for the benefit of coming generations，leave enough environmental space so that these generations will be able to address their needs and fulfill their aspirations.

　　结构分析:句子的框架是This need is enshrined in the concept of sustainable development…。其后紧跟着一个which引导的定语从句，修饰先行词sustainable development。此定语从句的谓语动词means又套嵌一个that引导的宾语从句，即we must…leave enough environmental space。此宾语从句中又有so that结构做此从句的目的状语。be enshrined in意为“被深深地珍藏（或铭记）在…”，此处转译为主动态“纳入到”。sustainable development译为“可持续发展”。

　　参考译文 这一需要能纳入到可持续发展的概念之中。所谓可持续发展是指:为了子孙后代的利益，我们必须保留足够的生存环境空间，以满足他们的需要，施展抱负。

　　经典例题491 Painting lacks only the means to represent movement in time and space，which is the special property of sculpture and architecture，since a painting is designed to be seen from one point at one time，whereas sculpture and architecture are created to be seen from various points of view，thus supplying movements in space and time.

　　结构分析:句子的框架是Painting lacks only the means…，since…。since引导的原因状语从句修饰主句;关系代词which引导的定语从句修饰the means to represent movement in time and space;property在此处应译为“性质，特性”，不译为“财产，资产”。

　　参考译文 绘画仅仅缺少的是表现空间与时间变化的手法，而这正是雕塑与建筑的特性。一幅画在绘制时就只要求在某一时刻，从空间的一点来欣赏，而雕塑和建筑的创造要求从各个角度来欣赏，这样就表现出了空间，时间的变化。

　　经典例题492 Once intimidated by arguments that their children would feel more at home in bilingual classes，and that they might lose their heritage in regular classes，these women have since given voice，loudly and persuasively，to what they know from experience that unless they are fluent in the language of their adopted country，their children will never attend college or land any but the most menial of jobs.

　　结构分析:句子的框架是these women have…given voice…to what they know from experience that…。that从句做what they know的同位语从句;此从句中又套嵌一个unless引导的条件状语从句;Once intimidated by arguments是过去分词做状语修饰these women，其施动者arguments又有两个that引导的同位语从句修饰限定它。intimidated by arguments意为“被论点搞得惊慌害怕”;feel at home不能直译为“感到在家”，而译为“感到自在”;give voice to意为“表达，表露”;land jobs译为“找到工作”。

　　参考译文 有人说，孩子们在双语课堂里会感到更加自由自在，而在正规班级会丧失其传统文化。这几位母亲曾被这一论点搞得惶恐不安，现在发表了最响亮，最有说服力的意见。从她们自身的经验中，他们深知:如果孩子们不熟练掌握他们所移居国家的语言，除了那些最简单的体力活儿外，根本谈不到上大学，也谈不到找到理想的工作。

　　经典例题493 The presumption on which human cloning rests is that all these cells，though now specialized，still contain exact copies of the original set of genetic instructions needed to make an entire individual—and can do so if a way is found to switch them back on.

　　结构分析:句子的框架是The presumption is that all these cells…contain genetic instructions…and can do so…。其中介词on加which引导定语从句修饰主语the presumption;that从句为表语从句;此表语从句中contain和can do并列做all these cells的谓语;

　　表语从句中又插入一个though引导的省略了主语all these cells的让步状语从句，补充完整

　　为though these cells are now specialized;needed to make an entire individual为过去分词短语做genetic instructions的后置定语;并列谓语can do so又有if条件句修饰。rest on意为“依赖，仰赖”。为避免重复do so代替前文提到的make an entire individual。

　　参考译文 人类无性生殖赖以存在的假想是:虽然所有的细胞现已全部特化，但却仍然包含有发育为完整个体所需的与母体完全一致的全部遗传指令;如果能找到一个方法使失去作用的部分恢复作用，这些细胞就能发育成为完整的个体。

　　经典例题494 Thus，a regularity for which there are general theoretical grounds for expecting it will be more readily called a natural law than an empirical regularity that cannot be subsumed under more general laws or theories.

　　结构分析:句子的框架是a regularity…will be more readily called a natural law than an empirical regularity…。介词for加关系代词which引导定语从句修饰a regularity。an empirical regularity后又有定语从句that cannot be subsumed under more general laws or theories修饰。grounds意为“根据，理由”;subsume意为“把…归入，纳入”。

　　参考译文 因此，与一条不能被归入更普遍的法则或理论而是基于经验的规律相比，一条具有普遍的理论依据支持的规律很可能被认可为一条自然法则。

　　经典例题495 It is because of the close association in most people’s minds of tools with man that special attention has always been focused upon any animal able to use an object as a tool，but it is important to realize that this ability，on it’s own，does not necessarily indicate any special intelligence in the creature concerned.

　　结构分析:句子的框架是It is because of…that…，but it is important to realize that…。but连接两个并列句，but前的并列分句为It is…that…强调结构，强调because of引导的状语。but后的并列分句又有that引导的宾语从句做realize的宾语。the close association in most people’s minds of tools with man中注意in most people’s minds把the close association of tools with man（工具与人类的密切联系）分隔开来。两个并列句中分别有able to use an object as a tool和concerned分别做其前面名词animal和the creature的后置定语。man根据上下文在此处指“人类”，而不是“男人”;not necessarily译为“不一定、未必”;on it’s own意为“独立地，凭自己力量”，在此转译为“就其自身而言”。

　　参考译文 正是由于在大多数人头脑中工具与人类的密切联系，人类才特别关注可以把物体当工具使用的任何一种动物，但值得注意的是，这种能力就其自身而言并不表明这种动物有什么特别的智慧。

　　经典例题496 The point at which tool_using and tool_making acquire evolutionary significance is surely when an animal can adapt its ability to manipulate objects to a wide variety of purposes，and when it can use an object spontaneously to solve a brand_new problem that without the use of a tool would prove insoluble.

　　结构分析:句子的框架是The point…is…when…and when…。两个when引导的从句为并列的表语从句。at which tool_using and tool_making acquire evolutionary significance为定语从句修饰主语the point;第二个when引导的表语从句中也有that引导的定语从句修饰a brand_new problem。ability to manipulate objects译为“操纵物体的能力”;…a brand_new problem that without the use of a tool would prove insoluble中without和insoluble为双重否定可译成肯定句。

　　参考译文 当一种动物能够使自己操纵物体的能力适用于更广泛的目标范围，并且能够自发地使用物体解决只有通过工具才能解决的崭新问题时，工具的使用和制造就肯定达到了具有进化意义的阶段。

　　经典例题497 It was the desire to be scholarly that brought about a wave of Latin terms which appeared in the16th century when the humanist movement brought new impetus to learning throughout Europe.

　　结构分析:句子的框架是It was the desire…that brought about a wave…。it is…that…是强调句型，强调主语the desire to be scholarly。关系代词which引导定语从句，修饰Latin terms;关系副词when引导定语从句，修饰century。句中scholarly作“博学多才”讲;humanist movement译为“人文主义运动”;impetus意为“动力，促进”。

　　参考译文 在16世纪的时候，人文主义运动促进了欧洲各国的学术运动，人们都想显示自己的博学多才，从而出现了一股使用拉丁字词的潮流。

　　经典例题498 So don’t be surprised if you never encounter some of the expressions that still appear in school textbooks;and next time you hear somebody using a strange word you haven’t heard before，you can comfort yourself that there may well be a native speaker somewhere who doesn’t know it either.

　　结构分析:句子的框架是…don’t be surprised if you…;and next time…，you can comfort yourself that…。分号连接两个并列分句。在前面句子中，if引导状语从句;关系代词that引导定语从句，修饰expressions。在后面句子中，you hear…是省略了关系副词when的定语从句，修饰next time;you haven’t heard before又是省略了关系代词which的定语从句，修饰strange word;主句是you can comfort yourself that…，这里的that引导宾语从句，而关系代词who引导定语从句，修饰native speaker。may和well连用表示有充分的理由，译为“（完全）能，（很）可能”。

　　参考译文 因此，如果在某些教科书里你碰到某些词组是你从未见过的，你不必惊讶。如果下次你听到有人用一个你以前从未听到过的新词，你可以这样安慰自己说，很可能在什么地方有一个讲英语的本地人也不认识这个字呢!

　　经典例题499 Despite the saying that one never knows if lightning strikes him，a person can sometimes feel the bolt coming and if quick enough，take protective action in time.

　　结构分析:句子的框架是a person can…feel the bolt and…take protective action…。and连接两个并列的谓语动词。句首despite是介词引导介词短语作状语，此短语中that引导的名词性从句做saying的同位语，此同位语从句中，if lightning…是一个名词性从句，作know的宾语，if在句中相当于whether。主句中if quick enough补充完整为if he is quick enough，是条件状语从句，为take action的前提条件。句中bolt译为“闪电”。

　　参考译文 尽管人们常说一个人从来不知道是否遭到闪电的袭击，但是一个人有时能感觉到闪电的到来，如果动作快，就能及时采取保护措施。

　　经典例题500 Part of the reason for the ambiguity of the term“law of nature”lies in the temptation to apply the term only to statements of one of these sorts of laws，as in the claim that science deals solely with cause and effect relationships，when in fact all three kinds are equally valid.

　　结构分析:句子的框架是the reason…lies in the temptation…。as引导状语从句，此状语从句中又有that从句做claim的同位语。此同位语从句中又套嵌一个when引导的时间状语

　　从句。ambiguity意为“意义不明确，模棱两可”;equally在此处不要译为“平等的”，而应译为“同样地”。

　　参考译文 “自然法则”这一术语之所以模糊不清，部分原因在于人们企图把这个术语仅用于指对这些法则中的某种法则。正如有人认为科学仅研究因果关系，但实际上它对三种都同样适用。

　　经典例题501 Aluminum remained unknown until the nineteenth century，because nowhere in nature is it found free，owing to its always being combined with other elements，most commonly with oxygen，for which it has a strong affinity.

　　结构分析:句子的框架是Aluminum remained unknown until…，because…。until the nineteenth century做主句的状语;because又引导原因状语从句，修饰主干结构;此状语从句中的主句nowhere in nature is it found free又是倒装句，正常语序为nowhere in nature it is found free。owing to为表原因的介词短语修饰nowhere in nature it is found free。介词in加关系代词which引导定语从句修饰oxygen。

　　参考译文 铝总是跟其他元素结合在一起，最普遍的是跟氧结合;因为铝跟氧有很强的亲和力，由于这个原因，在自然界找不到游离状态的铝。所以，铝直到19世纪才被人发现。

　　经典例题502 When a journalist recently accused the company of lacking integrity in its testing of beauty products，the company overtly appealed to the public by citing its corporate brand，which was firmly associated in people’s minds with strong ethical standards concerning animal rights.

　　结构分析:句子的框架是When…，the company overtly appealed to the public…。when引导时间状语从句。主句中关系代词which引导定语从句修饰corporate brand，此定语从句中in people’s minds把associated with分隔开来。beauty products译为“美容产品”。

　　参考译文 有一名记者近日指责该公司在美容产品的测试上缺乏整体性，该公司公开利用其公司品牌求助于公众，而该品牌在公众的心目中它已同关系到动物权利的道德标准息息相关。

　　经典例题503 However，the criminal fraternity quickly came to realize that the real value in the computers is in the chip which is remarkably portable and unidentifiable，so even when caught the police have trouble proving the theft.

　　结构分析:句子的框架是the fraternity…came to realize that…so…the police have trouble…。这是一个并列复合句，两个句子由so连接。在前面句子里that引导宾语从句，作realize的宾语;此从句中又有which引导的定语从句修饰the chip;so后面句子里when caught是过去分词作状语，when caught即when the thief was caught;proving是现在分词，修饰trouble。句子中criminal fraternity译为“偷盗贼们”。

　　参考译文 但偷盗者认识到，电脑中真正值钱的东西是芯片（或叫集成电路片），这是可以随身携带和无法识别的，即使当场被抓住，警察也难以证明那是偷来的。

　　经典例题504 Although perhaps only1percent of the life that has started somewhere will develop into highly complex and intelligent patterns，so vast is the number of planets that intelligent life is bound to be a natural part of the universe.

　　结构分析:句子的框架是Although…，so vast is the number of planets that…。主句为so…that…结构引导的结果状语从句，因强调vast，so vast放在句首进行倒装，正常语序为the number of planets is so vast that…。although引导让步状语从句。此从句中套嵌一个关系代词that引导的定语从句修饰life。be bound to意为“一定，必定”。

　　参考译文 虽然在某处已经开始的生命中可能仅有百分之一会发展成高度复杂、有智慧的形式，但是行星的数目如此之多，以致有智慧的生命一定是宇宙的一个天然组成部分。