亲爱的备考
下文是从TPO中精心挑选的长难句，也是很多同学在实际学习中遇到问题最多的句子，同时附上35个托福阅读经典长难句解析，供有需要的同学可以参考：
1. Accordingto conventional theory, yawning takes place when people are bored or sleepy andserves the function of increasing alertness by reversing, through deeperbreathing, the drop in blood oxygen levels that are caused by the shallowbreathing that accompanies lack of sleep or boredom.
【译文】根据传统的理论，当人们无聊或者困倦的时候，打哈欠会出现。打哈欠通过深呼吸来逆转血液中氧含量的降低，从而的起到提高警觉的功能。而血液中氧含量的降低是由浅呼吸导致的，而浅呼吸又伴随着缺觉或无聊。
2. The keyfactor in the success of these countries (along with high literacy, whichcontributed to it) was their ability to adapt to the international division oflabor determined by the early industrializers and to stake out areas ofspecialization in international markets for which they were especially wellsuited.
【译文】这些国家成功的关键因素(促成这个因素的是高识字率)是他们有能力适应由早期的工业化国家决定的劳动力国际分工并占领了他们特别适合的国际市场中的专业化领域。
3. In the second case, pollinators(insects, birds) obtain food from the flowering plant, and the plant has itspollen distributed and seeds dispersed much more efficiently than they would beif they were carried by the wind only.
【译文】在第二个案例中， 传粉者(昆虫和鸟)从开花植物中获取食物，而植物也使得它们的花粉和种子相比于只通过风传播的更加高效。
4. In the green-to yellow lightingconditions of the lowest levels of the forest, yellow and green would be thebrightest colors, but when an animal is signaling, these colors would not bevery visible if the animal was sitting in an area with a yellowish or greenishbackground.
【译文】在森林最底层的黄绿管线条件下，黄和率可能是最亮的颜色，但是，当动物在发信号的时候，如果该动物处于黄绿背景下，这些颜色就不太明显了。
5. In a countercurrent exchange system, the blood vesselscarrying cooled blood from the flippers run close enough to the blood vessels carrying warmblood from the body to pick up some heat from the warmer blood vessels; thus,the heat is transferred from the outgoing to the ingoing vessels before itreaches the flipper itself.
【译文】在逆流交换系统中，来自于脚蹼的携带冷血的血管接近来自身体的携带热血的血管来从较热的血管中获得热量;因此，在达到脚蹼前，热量从向外流的血管中转移到了向内流的血管中。
6. American paleontologists David Raup and John Sepkoski,who have studied extinction rates in a number of fossil groups, suggest thatepisodes of increased extinction have recurred periodically, approximatelyevery 26 million years since the mid-Cretaceous period.
【译文】美国古生物学家D.R.和J.S，他们已经很多化石群的灭绝速率，指出，越来越多的灭绝是周期性重复出现的，从白垩纪中期开始，周期大约是没二百六十万年一次。
7. As amongtribes people, personal relationships and a careful weighing of character havealways been crucial in a mercantile economy with little regulation, where one'sword is one's bond and where informal ties of trust cement together aninternational trade network.
【译文】在部落人中，人际关系和对品德仔细的考量在一个几乎没有规范的重商主义经济中一直都很重要。而在没有规范的重商主义经济中，一个的话语就是一个人的保证，非正式的信任纽带将国际贸易网络年合起来。
8. The explanation is that the Mayaexcavated depressions, or modified natural depressions, and then plugged upleaks in the karst by plastering the bottoms of the depressions in order tocreate reservoirs, which collected rain from large plastered catchment basinsand stored it for use in the dry season.
【译文】解释是，玛雅人挖掘了大坑或者将天然的大坑修改，然后又通过把大坑的底部抹上灰泥把卡斯特地貌上的漏洞堵上，来制造蓄水池，这样，就能从巨大的被灰泥堵住的蓄水池中收集雨水并储存起来在干季时使用。
9. Inequalitiesof gender have also existed in pastoralist societies, but they seem to havebeen softened by the absence of steep hierarchies of wealth in mostcommunities, and also by the requirement that women acquire most of the skillsof men, including, often, their military skills.
【译文】性别的不平等也存在于畜牧社会中，但是，由于大部分社群中没有出现森严的财富等级，而且需要女性具备大多数男性的技巧，诸如军技巧，性别不平等就被软化了。
10. Ramsay thenstudied a gas that was present in natural gas deposits and discovered that itwas helium, an element whose presence in the Sun had been noted earlier in thespectrum of sunlight but that had notpreviously been known on Earth.
【译文】拉姆齐(Ramsay)研究了一种存在于天然气中的气体，并发现是氦气(helium)，该元素早就在太阳里通过太阳光光谱被发现了，但是还从来没有在地球上被发现过。
11. Many complex factors led to the adoption of the neweconomies, not only at Abu Hureyra, but at many other locations such as 'AinGhazal, also in Syria, where goat toe bones showing the telltale marks ofabrasion caused by foot tethering (binding) testify to early herding of domesticstock.
【译文】很多复杂的因素导致了新经济的采用，不仅出现在AbuHureyra，很多其他的地方也有，比如说'AinGhaza,也就是叙利亚，在那里，山羊脚趾的骨头显示有脚被绑住造成的磨损痕迹，这证实了早期的家畜蓄养。
附：
1、Totally without light and subjected to intense pressures hundreds of times greater than at the Earth’s surface，the deep—ocean bottom is a hostile environment to humans，in some ways as forbidding and remote as the void of outer space.
(定语后置in some ways…)
【译句】由于完全没有光，而且承受着比在地球表面大数百倍的极大压力，深海底部对人类而言是一个充满敌意的环境，在某些方面就像外层空间一样险恶和遥远。
分句1：Totally without light and subjected to intense pressures
分句2：hundreds of times greater than at the Earth’s surface
分句3：the deep—ocean bottom is a hostile environment to humans
分句4：in some ways as forbidding and remote as the void of outer space
分句2修饰分句1结尾的短语intense pressures，
分句1是分句3的状语
分句3是整个长句子的主句
分句4是分句3的后置定语，修饰分句3的a hostile environment to humans
主句前后分别有状语和定语的修饰成分，但是本句其实不是复合句。句子的核心意思是深海对于人类而言是一个充满敌意的环境。
2、Basic to any understanding of Canada in the 20 years after the Second World War is the country's impressive population growth.
(倒装结构Basic to any understanding…is…)
要理解二战之后20年中的加拿大，就必须了解该国惊人的人口增长。
分句1：Basic to any understanding of Canada in the 20 years after the Second World War
分句2：is
分句3：the country's impressive population growth
分句1，2，3共同构成倒装句，正常的语序应该是3，2，1，即：该句的正常语序是The country's impressive population growth is basic to any understanding of Canada in the 20 years after the Second World War.
本句是一个简单句，只不过使用了倒装，谓语动词是is.
3、As a result，claims that eating a diet consisting entirely of organically grown foods prevents or cures disease or provides other benefits to health have become widely publicized and form the basis for folklore.
(同位语从句claims that…)
结果，那些认为只食用绿色食品就能防治疾病或增进健康的观点广为人知，并成为一些民间说法的基础。
分句1： that eating a diet consisting entirely of organically grown foods prevents or cures disease or provides other benefits to health
分句2： claims have become widely publicized and form the basis for folklore
分句1作为分句2主语 "claim" 的同位语从句嵌套在分句2中。因此本句的主句就是分句2. 同位语从句是that eating a diet consisting entirely of organically grown foods prevents or cures disease or provides other benefits to health：吃有机食品就能防治疾病或增进健康。
4、There are numerous unsubstantiated reports that natural vitamins are superior to synthetic ones，that fertilized eggs are nutritionally superior to unfertilized eggs，that untreated grains are better than fumigated grains and the like.
(并列同位语从句reports that…，that…，that…)
关于天然维生素优于人造维生素，受精蛋比未受精蛋的营养价值更高，未经熏蒸消毒处理的谷物比经过处理的好等等报道屡见不鲜，但都没有得到证实。
分句1：There are numerous unsubstantiated reports
分句2：that natural vitamins are superior to synthetic ones
分句3：that fertilized eggs are nutritionally superior to unfertilized eggs
分句4：that untreated grains are better than fumigated grains and the like
分句1是整个长句的主句，分句2、分句3和分句4是并列关系，共同构成分句1的同位语从句。本句的意思是有很多没有经过证实的报道，然后并列了三个未经过证实的报道的从句。
5、The desperate plight of the South has eclipsed the fact that reconstruction had to be undertaken also in the North，though less spectacularly.
(同位语从句fact that…)
南方极为严重的困境使北方同样需要开始重建(尽管不像南方那么引人注目)这一事实显得不太重要。
分句1. The desperate plight of the South has eclipsed the fact
分句2. that reconstruction had to be undertaken also in the North
分句3. though less spectacularly (省略)
分句2是嵌套在分句1中的，做分句1中的fact的同位语从句。
分句3是分句2中的让步状语从句，并有省略现象存在，完整的说法是： though the reconstruction is less spectacular.
6、The new accessibility of land around the periphery of almost every major city sparked an explosion of real estate development and fueled what we now know as urban sprawl.
(宾语从句what we now know as)
现在可以获得这些环绕几乎每个大城市边缘地区的土地，这一可能性激发了一场房地产开发的热潮并造成了我们现在称为城区无计划扩展的现象。
分句1：The new accessibility of land around the periphery of almost every major city sparked an explosion of real estate development and fueled
分句2：what we now know as urban sprawl
分句2嵌套在分句1里，即分句1是主句，分句2是宾语从句，主句结构经过精简应该是The new accessibility of land sparked an explosion of real estate development and fueled urban sprawl.
整句话的谓语动词是 sparked 和 fueled, 两个并列的动词。
本句的理解困难还来自于抽象词fuel，它作为名词的含义广为人知，是能源、燃料，作为动词的时候的意思就可以引申为(供给燃料)激发，促使、造成。
7、But these factors do not account for the interesting question of how there came to be such a concentration of pregnant ichthyosaurs in a particular place very close to their time of giving birth.
(Of结构作定语：of how there came to be such a concentration of pregnant ichthyosaurs…)
但这些因素并不能解释这个有趣的问题：为何在一个特定的地点会如此集中地出现即将临产的怀孕鱼龙群。
分句1： But these factors do not account for the interesting question
分句2： of how there came to be such a concentration of pregnant ichthyosaurs in a particular place very close to their time of giving birth
分句1中嵌套着分句2.
分句2是of结构作后置定语修饰说明question的内容。
8、Amid rumors that there were prehistoric mammoths wandering around the unknown region and that somewhere in its wilds was a mountain of rock salt 80 by 45 miles in extent，the two captains set out.
(同位语从句rumors that…)
当时有一些传言，说有史前的猛犸在这一陌生的区域活动，而且在这一区域的某个地方有一座巨大的盐石山，其面积达80英里长50英里宽。就在这些传言中，两位上尉出发了。
分句1：Amid rumors
分句2：that there were prehistoric mammoths wandering around the unknown region
分句3：and that somewhere in its wilds was a mountain of rock salt 80 by 45 miles in extent
分句4：the two captains set out.
整个句子的主句是分句4.
"Amid" 表示“在 ......之中", 是介词，它引导的分句1嵌套着分句2和分句3，并且在整句话中作状语。 而分句2和分句3是并列关系的同位语从句来修饰分句1中的rumors，作rumors的同位语从句，用来说明谣言的具体内容。
9、In the seventeenth century the organ, the clavichord, and the harpsichord became the chief instruments of the keyboard group，a supremacy they maintained until the piano supplanted them at the end of the eighteenth century.
(同位语a supremacy)
17世纪时风琴、敲弦琴和拨弦琴成为键盘乐器类的主要成员，这种至高无上的地位一直由它们保持，直到18世纪末被钢琴所取代。
分句1：In the seventeenth century the organ, the clavichord, and the harpsichord became the chief instruments of the keyboard group，
分句2：a supremacy
分句3：they maintained until the piano supplanted them at the end of the eighteenth century
分句2是分句1的同位语，用来修饰说明分句1中的the chief instruments of the keyboard group，分句3是省略了 "that" 的定语从句，修饰分句2.
10、A series of mechanical improvements continuing well into the nineteenth century, including the introduction of pedals to sustain tone or to soften it, the perfection of a metal frame and steel wire of the finest quality, finally produced an instrument capable of myriad tonal effects from the most delicate harmonies to an almost orchestral fullness of sound，from a liquid，singing tone to a sharp, percussive brilliance.
(介词结构from…to…作定语)
持续到19世纪的一系列机械上的改进，包括引入踏板以维持音调或使其柔和，改善金属框架，以及使用最佳牲能的钢丝，最终产生了一种具备无数音调效果的乐器——这些效果涵盖了从最精致的和声到几乎全部的管弦乐音响，从明快流畅的吟唱音调到尖锐的打击乐器的恢弘气氛。
分句1：A series of mechanical improvements continuing well into the nineteenth century;
分句2：including the introduction of pedals to sustain tone or to soften it;
分句3：the perfection of a metal frame and steel wire of the finest quality;
分句4：finally produced an instrument capable of myriad tonal effects;
分句5：from the most delicate harmonies to an almost orchestral fullness of sound;
分句6：from a liquid，singing tone to a sharp, percussive brilliance。
本句的真正的主句结构其实是由分句1和分句4构成，即A series of mechanical improvements continuing well into the nineteenth century finally produced an instrument capable of myriad tonal effects. 分句2和分句3并列修饰说明分句1中的A series of mechanical improvements，而分句5和分句6并列，修饰说明了分句4中的an instrument capable of myriad tonal effects.
11、The largest later named Pueblo Bonito(Pretty Town)by the Spanish, rose in five terraced stories，contained more than 800 rooms，and could have housed a population of 1，000 or more.
【译句】最大的一座后来被西班牙人称为Pueblo Bonito(美丽的城镇)，是一个五层梯式楼，有800多间房子，能够容纳1 000人以上。
分句1：The largest rose in five terraced stories，contained more than 800 rooms，and could have housed a population of 1，000 or more;
分句2：later named Pueblo Bonito(Pretty Town)by the Spanish。
分句1嵌套了分句2，分句1的主语是the largest, 这是“the + 形容词”表示一个名词的结构，相当于“the largest one" 的省略的说法。
分句2是省略了“which was" 的定语从句，用来修饰分句1的主语the largest, 分句1内部是由三个并列的谓语构成的句子。
12、Accustomed though we are to speaking of the films made before 1927 as “silent”，the film has never been，in the full sense of the word, silent.
(倒装accustomed though we are…=though we are accustomed…)
【译句】虽然我们习惯于将1927年以前的电影叫做“无声电影”，但是就“无声’’这个词的完整意义上说，电影从未真正的无声过。
分句1：Accustomed though we are to speaking of the films made before 1927 as “silent”;
分句2：the film has never been silent;
分句3：in the full sense of the word;
本句的难点是在分句1是倒装句，正常语序是Though we are accustomed to speaking of the films made before 1927 as silent. 分句3是一个插入语，嵌套在分句2中，所以本句真正强调的核心是the film has never been silent.
13、For a number of years the selection of music for each film program rested entirely in the hands of the conductor or leader of the orchestra，and very often the principal qualification for holding such a position was not skill or taste so much as the ownership of a large personal library of musical pieces.
(特殊结构not…SO much as…——与其说…不如说…)
【译句】在好些年内，为各部影片选择配乐的权力完全掌握在乐队指挥或队长手中，而通常担任这种职位的资格与其说是技巧或鉴赏品位，不如说是个人拥有音乐作品的丰富收藏。
分句1：.For a number of years the selection of music for each film program rested entirely in the hands of the conductor or leader of the orchestra;
分句2：and very often the principal qualification far holding such a position was not skill or taste so much as the ownership of a large personal library of musical pieces;
分句1 和分句2是两个并列关系的分句，分句2的难点在于not…… so much as的结构。
14、Coincident with concerns about the accelerating loss of species and habitats has been a growing appreciation of the importance of biological diversity，the number of species in a particular ecosystem，to the health of the Earth and human well-being.
(倒装coincident with concerns…has been…=…has been coincident with concerns…)
【译句】在对物种和动物栖息地加速消失表示关注的同时，人们也越来越认识到生物多样化，即一个特定生态系统中物种的数量对地球的健康以及人类幸福的重要性。
此句是完全倒装句，谓语动词是 has been，真正的主语是has been 后面的内容。Coincident with concerns about the accelerating loss of species and habitats是表语。
原来的正常语序是： A growing appreciation of the importance of biological diversity，the number of species in a particular ecosystem，to the health of the Earth and human well-being has been coincident with concerns about the accelerating loss of species and habitats
其中 the number of species in a particular ecosystem 是插入语，作为同位语出现，用来解释说明biological diversity。
在这句话真正的主语中有一个 " the importance of A to B" 的结构，应该翻译为“A对B的重要性”。 原句中就是 "the importance of biological diversity to the health of the Earth and human well-being " 叫做“生物多样性对于地球和人类幸福健康的重要性"。
15、The fact that half of the known species are thought to inhabit the world's rain forests does not seem surprising，considering the huge numbers of insects that comprise the bulk of the species.
(同位语从句fact that…;定语从句that comprise the bulk…)
【译句】考虑到组成大部分物种的昆虫的巨大数量，认为半数的已知物种栖息在世界的雨林中这一事实看起来并不令人吃惊。
分句1：The fact does not seem surprising.
分句2：that half of the known species are thought to inhabit the world's rain forests
分句3：considering the huge numbers of insects
分句4：that comprise the bulk of the species
分句1中嵌套着分句2，分句2解释说明分句1的主语the fact, 是同位语从句;分句3是主句的状语，分句4是定语从句，修饰分句3的the huge numbers of insects
16、To appreciate fully the diversity and abundance of life in the sea，it helps to think small.
(特殊结构it helps to…做…有帮助)
【译句】要充分认识海洋生命的多样性和丰富性，从小的角度思考有帮助。
目的状语：To appreciate fully the diversity and abundance of life in the sea,主句： it helps to think small. (这里的it是形式主语，没有实际意义)
17、Science is built with facts just as a house is built with bricks，but a collection of facts cannot be called science any more than a pile of bricks can be called a house.
(特殊结构not any more than像…一样不…)
【译句】科学建立在事实上，就像房子用砖砌成一样。但收集的事实不能被叫做科学，就像一堆砖不能被称为房子一样。
分句1： Science is built with facts
分句2： just as a house is built with bricks,
分句3： but a collection of facts cannot be called science any more than a pile of bricks can be called a house.
这句话的难点在于“not ... any more than 像…一样不…”，相当于“a pile of bricks cannot be called a house"，
18、In a period characterized by the abandonment of so much of the realistic tradition by authors such as John Barth，Donald Barthelme，and Thomas Pynchon, Joyce Carol Oates has seemed at times determinedly old-fashioned in her insistence on the essentially mimetic quality of her fiction.
(特殊结构characterized by…——以…为特征)
【译句】尽管处于一个以抛弃大量现实主义传统(以作家约翰•巴思、唐纳德•巴塞尔姆和托马斯.品钦为代表)为特征的时代，乔伊斯•卡罗尔•欧茨因为坚持自己小说本质上模仿的特点，有时候看起来是一个坚定的守旧派。
分句1. characterized by the abandonment of so much of the realistic tradition by authors such as John Barth，Donald Barthelme，and Thomas Pynchon,
分句2. Joyce Carol Oates has seemed at times determinedly old-fashioned in her insistence OD the essentially mimetic quality of her fiction.
分句1 做时间状语“In a period”的后置定语，补充修饰period，相当于省略了 “which was”的定语从句。 分句2 是主句。
整个句子的难点在于找主句。 其实分句1的末尾是 "such as" 引导的三个人名的并列，在最后一个人名Thomas Pynchon前有"and", 说明这个列举对象中的最后一个。所以整个句子的主干在T P 这个人后面出现。
19、If it were not for this faculty, they would devour all the food available in short time and would probably starve themselves out of existence.
(虚拟语气)
【译句】如果不是具有这种能力，它们就会在短时间内吞掉所有能得到的食物，而且很可能会因饿死而灭绝。
分句1. If it were not for this faculty
分句2. they would devour all the food available in short time
分句3. would probably starve themselves out of existence
分句1 是虚拟语气的条件从句
分句2、3是并列关系，并且是主句。
20、People in the United States in the nineteenth century were haunted by the prospect that unprecedented change in the nation's economy would bring social chaos.
(同位语从句prospect that…)
【译句】19世纪的美国人因为害怕国家经济中史无前例的变化会带来社会混乱这一前景而提心吊胆。
分句1. People in the United States in the nineteenth century were haunted by the prospect;
分句2. that unprecedented change in the nation's economy would bring social chaos.
2嵌套在1中，做1中prospect 的同位语从句;1是主句，2 具体解释说明 prospect。
21、Accompanying that growth was a structural change that featured increasing economic diversification and a gradual shift in the nation's labor force from agriculture to manufacturing and other nonagricultural pursuits.
(倒装Accompanying that growth was a structural change that…=A structural change…was accompanying that growth)
【译句】伴随着这一增长的是一个结构变化，它以经济的不断多样化和国家劳动力从农业到制造业和其他非农业职业的逐渐转化为特征。
分句1. Accompanying that growth was a structural change
分句2. that featured increasing economic diversification and a gradual shift in the nation's labor force from agriculture to manufacturing and other nonagricultural pursuits
2嵌套在1中，做1中的structural change 的定语从句，这个定语从句结构较复杂，由两个and连接三个并列的名词性成分。
分句1是主句，且采用完全倒装的形式。
22、As the roles men and women played in society became more rigidly defined, so did the roles they played in the home.
(倒装so did…)
【译句】随着男人和女人在社会中扮演的角色被限定得更加严格，他们在家中的角色也是如此。
分句1. the roles became more rigidly defined
分句2. men and women played in society
分句3. so did the roles
分句4. they played in the home.
1和2嵌套，2是修饰1中的role 的定语从句。 3和4嵌套，4是3中的roles的。
1和3并列，3是由so引导的部分倒装句。
23、Surrounding the column are three sepals and three petals，sometimes easily recognizable as such，often distorted into gorgeous，weird，but always functional shapes.
(倒装Surrounding the column are…)
【译句】围绕着蕊柱的是三个萼片和三个花瓣，有时很容易辨认出来，但经常被扭成华丽、奇特但总是有用的形状。
完全倒装句，正常语序是：
Three sepals and three petals are surrounding the column, sometimes easily recognizable as such，often distorted into gorgeous，weird，but always functional shapes.
24、With the growing prosperity brought on by the Second World War and the economic boom that followed it，young people married and established households earlier and began to raise larger families than had their predecessors during the Depression.
(倒装than had their predecessors—比较结构的第二部分)
【译句】随着二战带来的持续繁荣以及随之而来的经济增长，年轻人比大萧条中的同龄人结婚成家更早，而且养育的家庭比他们的前辈更大。
分句1. the growing prosperity brought on by the Second World War
分句2. the economic boom that followed it
分句3. young people married and established households earlier
分句4. began to raise larger families than had their predecessors during the Depression.
1和2并列，3和4并列
1和2 是伴随状语
3和4是主句
25、The railroad could be and was a despoiler of nature;furthermore，in its manifestation of speed and noise，it might be a despoiler of human nature as well.
(关联结构could be and was)
【译句】铁路可以，事实上也是自然的掠夺者;而且，在其速度和噪音的表现上也可能是人性的掠夺者。
分句1. The railroad could be and was a despoiler of nature
分句2. it might be a despoiler of human nature as well.
1和2 是并列 (由分号连接的两个并列分句)。
26、In the railroads' prime years，between 1 890 and 1920，there were a few individuals in the United States，most of them with solid railroading experience behind them，who made a profession of writing about railroading--works offering the ambience of stations，yards，and locomotive cabs.
(同位语most of them;定语从句who made a profession of writing)
【译句】在1890年到1920年间铁路的黄金时期，美国有几个人(他们大多有丰富的铁路经验)以写铁路题材为职业——作品围绕车站、停车场和机车。
分句1. there were a few individuals in the United States
分句2. most of them with solid railroading experience behind them
分句3. who made a profession of writing about railroading
分句4. works offering the ambience of stations，yards，and locomotive cabs.
1是主句
2和3是嵌套
2作为1中a few individuals 的同位语，对它进一步解释说明
27、On the other hand，when it comes to substantive--particularly behavioral-information，crows are less well known than many comparably common species and，for that matter，not a few quite uncommon ones：the endangered California condor，to cite one obvious example.
(特殊结构for that matter)
【译句】另一方面，当涉及实质性的，特别是行为方面的信息时，乌鸦就不如许多比较而言很普通的鸟类那样为人所知;而且，也不如许多很不寻常的鸟类，举一个明显的例子，如像濒危的加利福尼亚大秃鹫那样为人所知。
分句1. when it comes to substantive--particularly behavioral-information;
分句2. crows are less well known than many comparably common species and, for that matter，not a few quite uncommon ones：the endangered California condor，to cite one obvious example.
1和2是并列， 分句1是时间状语， 2是主句，其中包含插入语结构 以及 冒号连接的解释说明的成分。
28、Keen observers and quick learners，they are astute about the intentions of other creatures，including researchers，and adept at avoiding them.
(并列同位语keen observers and quick learners)
【译句】乌鸦是敏锐的观察家和快捷的学习者，它们对其他生物(包括研究人员)的意图感觉非常敏锐，并且善于躲开它们。
分句1. they are astute about the intentions of other creatures，including researchers;
分句2. and adept at avoiding them.
1和2是并列。 句子开头的“keen observers and quick learners”是主语 they的同位语。
29、These researchers have sought to demonstrate that their work can be a valuable tool not only of science but also of history，providing flesh insights into the daily lives of ordinary people whose existences might not otherwise be so well documented.
(宾语从句demonstrate that…;特殊结构otherwise)
【译句】这些研究人员已经力图证实他们的工作不仅可以成为科学而且还是历史的宝贵工具，为了解普通人的日常生活提供崭新的观点，否则这些普通人的生存状态不可能被记载得这么好。
分句1：These researchers have sought to demonstrate that;
分句2：their work can be a valuable tool not only of science but also of history;
分句3：providing flesh insights into the daily lives of ordinary people;
分句4：whose existences might not otherwise be so well documented.
分句1是整个长句子的主句
分句2是分句1的宾语从句
分句3是以现在分词形式表示伴随状态
分句4是分句3的定语从句。
30、Legend has it that sometime toward the end of the Civil War(1861--1865)a government train carrying oxen traveling through the northern plains of eastern Wyoming was caught in a snowstorm and had to be abandoned.
(特殊结构Legend has it that…=There is a legend that…)
【译句】传说在内战(1861--1865)快结束的某个时候，一列载着牛群的政府的火车在穿过怀俄明州东部的北部平原时遇到了暴风雪，因此不得不被遗弃。
分句1：Legend has it that
分句2：sometime toward the end of the Civil War(1861--1865)a government train carrying oxen traveling through the northern plains of eastern Wyoming was caught in a snowstorm
分句3：and had to be abandoned
分句1是整个长句子的形式主句
分句2是分句1的具体解释，也是真正的主句。这里出现了几个分词形式，如“carrying oxen” “traveling through……”等，完全可以换成“that/which carries……”，这里都是现在分词做后置定语，起修饰限定作用。
分句3是2的并列。
31、It is a lifelong process，a process that starts long before the start of school and one that should be an integral part of one's entire life.
(并列同位语a process that…，and one that…)
【译句】教育是一个终生的过程，早在人们上学之前就开始了。它应成为人的一生中不可缺少的一部分。
分句1：It is a lifelong process，
分句2：a process that starts long before the start of school;
分句3：and one that should be an integral part of one's entire life。
分句1是整个长句子的形式主句
分句2是分句1的同位语，是对1的进一步解释说明
分句3是2的并列句，同为对1的解释说明
32、Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.
(特殊结构as much…as;倒装as was the genesis of life)
【译句】生命从海洋到陆地的过渡可能是一个像生命起源那样的进化挑战。
分句1：Life's transition from the sea to the land was perhaps as much of an evolutionary challenge
分句2：as was the genesis of life
分句1是整个长句子的主句，虽然这一部分很长，但主谓宾只有一套，而且顺序是正常的分句2是倒装句，按正当语序相当于“the genesis of life was as……(省略)”
另外有一则好消息，针对托福备考，