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2017年考研英语专项训练题及答案
阅读理解
篇一：
Although recent years have seen substantial reductions in noxious pollutants from individual motor vehicles, the number of such vehicles has been steadily increasing. Consequently, more than 100 cities in the United States still have levels of carbon monoxide, particulate matter, and ozone (generated by photochemical reactions with hydrocarbons from vehicle exhaust) that exceed legally established limits. There is a growing realization that the only effective way to achieve further reductions in vehicle emissions — short of a massive shift away from the private automobile — is to replace conventional diesel fuel and gasoline with cleaner-burning fuels such as compressed natural gas, liquefied petroleum gas, ethanol, or methanol.
All of these alternatives are carbon-based fuels whose molecules are smaller and simpler than those of gasoline. These molecules burn more cleanly than gasoline, in part because they have fewer, if any, carbon-carbon bonds and the hydrocarbons they do emit are less likely to generate ozone. The combustion of larger molecules, which have multiple carbon-carbon bonds involves a more complex series of reactions. These reactions increase the probability of incomplete combustion and are more likely to release uncombusted and photochemically active hydrocarbon compounds into the atmosphere. On the other hand, alternative fuels do have drawbacks. Compressed natural gas would require that vehicles have set of heavy fuel tanks — a serious liability in terms of performance and fuel efficiency — and liquefied petroleum gas faces fundamental limits on supply.
Ethanol and methanol, on the other hand, have important advantages over other carbon-based alternative fuels: they have higher energy content per volume and would require minimal changes in the existing network for distributing motor fuel. Ethanol is commonly used as a gasoline supplement, but it is currently about twice as expensive as methanol, the low cost of which is one of its attractive features. Methanol’s most attractive feature, however, is that it can reduce by about 90 percent the vehicle emissions that form ozone, the most serious urban air pollutant.
Like any alternative fuel, methanol has its critics. Yet much of the criticism is based on the use of “gasoline clone” vehicles that do not incorporate even the simplest design improvements that are made possible with the use of methanol. It is true, for example, that a given volume of methanol provides only about one-half of the energy that gasoline and diesel fuel do; other things being equal, the fuel tank would have to be somewhat larger and heavier. However, since methanol-fueled vehicles could be designed to be much more efficient than “gasoline clone” vehicles fueled with methanol they would need comparatively less fuel. Vehicles incorporating only the simplest of the engine improvements that methanol makes feasible would still contribute to an immediate lessening of urban air pollution.
1. The author of the text is primarily concerned with
[A] countering a flawed argument that dismisses a possible solution to a problem.
[B] reconciling contradictory points of view about the nature of a problem.
[C] identifying the strengths of possible solutions to a problem.
[D] discussing a problem and arguing in favor of one solution to it.
2. According to the text, incomplete combustion is more likely to occur with gasoline than with an alternative fuel because
[A] the combustion of gasoline releases photochemically active hydrocarbons.
[B] the combustion of gasoline embraces an intricate set of reactions.
[C] gasoline molecules have a simple molecular structure.
[D] gasoline is composed of small molecules.
3. The text suggests which of the following about air pollution?
[A] Further attempts to reduce emissions from gasoline-fueled vehicles will not help lower urban air-pollution levels.
[B] Attempts to reduce the pollutants that an individual gasoline-fueled vehicle emits have been largely unsuccessful.
[C] Few serious attempts have been made to reduce the amount of pollutants emitted by gasoline-fueled vehicles.
[D] Pollutants emitted by gasoline-fueled vehicles are not the most critical source of urban air pollution.
4. Which of the following most closely parallels the situation described in the first sentence of the text?
[A] Although a town reduces its public services in order to avoid a tax increase, the town’s tax rate exceeds that of other towns in the surrounding area.
[B] Although a state passes strict laws to limit the type of toxic material that can be disposed of in public landfills, illegal dumping continues to increase.
[C] Although a town’s citizens reduce their individual use of water, the town’s water supplies continue to dwindle because of a steady increase in the total populating of the town.
[D] Although a country attempts to increase the sale of domestic goods by adding a tax to the price of imported goods, the sale of imported goods within the country continues to increase.
5. It can be inferred that the author of the text most likely regards the criticism of methanol as
[A] flawed because of the assumptions on which it is based.
[B] inapplicable because of an inconsistency in the critics’ arguments.
[C] misguided because of its exclusively technological focus.
[D] inaccurate because it ignores consumers’ concerns.
[答案与考点解析]
1. 【答案】C
【考点解析】这是一道中心主旨题。本文的中心主旨句是首段的尾句。通过对首段尾句以及其它段落主题句的阅读和理解，可以推导出本题的正确选项是C。考生在破解此类题型时一定要首先抓住原文的中心主旨句以及各段的主题句。
2. 【答案】B
【考点解析】本题是一道指代词题型。根据题干中的“incomplete combustion”可将本题的答案信息来源迅速确定在第二段的第四句，该句中的指代词“these”暗示本题的具体答案信息来源应该在第二段的第三句。通过阅读和理解第二段的第三句可推导出本题的正确选项是B。考生在解题时对指代词一定要认真理解。
3. 【答案】A
【考点解析】本题是一道审题定位题型。通过题干中的“air pollution”可将本题的答案信息来源迅速确定在第一段，因为第一段首句中含有“noxious pollutants”，都在谈污染的问题。通过阅读和理解第一段，尤其是第一段尾句即全文的中心主旨句，可推导出本题的正确选项是A。这是一道比较难的题。考生在解题时一定要具备审题定位能力，还要具备归纳和推导能力。
4. 【答案】C
【考点解析】这是一道类比题型，因为本题题干中含有“parallels”(与……相当，与……一样)一词。本题题干已将类比的参照对象确定在第一段的首句。通过仔细阅读和理解第一段的首句，可推导出本题的正确选项是C，因为该选项涉及的增减关系的前提条件和原文一脉相承。考生在破解这种题型时应对原文所表达的内容与关系有明确的认识和把握，不可以无根据地推导。
5. 【答案】A
【考点解析】这是一道细节推导题型。本题题干中的“the criticism of methanol”把本题的答案信息来源确定在第四段的第一、二句。通过阅读和理解这两句话，尤其是第二句话，就可推导出本题的正确选项A。考生在破解本题时一定要注意第二句话的第一个词“Yet”在语意上所起的作用。考生在解题时一定要重视启承转合词的出现和功能。
[参考译文]
近年来，尽管单个机动车辆排放的有毒污染物已大幅减少，但这些机动车辆的数量一直在持续增长，结果是，在美国有100多个城市的大气中一氧化碳、灰尘和臭氧(由车辆尾气中的碳氢化合物经光化反应产生)的含量已超出了法定的限度。人们愈来愈认识到，实现车辆废气进一步减少而又不必大规模减少私家轿车的唯一有效途径是用清洁燃料来代替传统的柴油和汽油燃料。这些清洁燃料包括压缩天然气、液化石油气、乙醇和甲醇。
所有这些替代产品都是碳基燃料，不过它们的分子要比汽油的分子小且简单。它们可以比汽油燃烧得更彻底，部分原因在于，即使它们含有碳—碳化学键，含量也较少，而且它们释放的碳氢化合物也不大可能产生臭氧。那些具有多重碳——碳化学键的大分子在燃烧时包含了一系列复杂的反应。这些反应增大了不完全燃烧的可能，并且更容易释放未燃烧的碳氢化合物，而这些化合物又对光化学反应很活跃。另一方面，这些替代燃料也有自己的缺点。压缩天然气可能需要车辆配备一个笨重的油箱，这对车辆性能和燃料效率又极为不利，并且液化石油气还面临着供应上的根本限制。
从另一方面来看，甲醇和乙醇与其它的碳基替代燃料相比有重要的益处：它们具有单位体积更高的能量含量，而且对现存的燃料销售网络只需很小地改变。乙醇通常作为汽油的替代品，但目前它比甲醇要贵两倍，因此甲醇的低廉价格便成为引人注目的特点。然而，甲醇最吸引人的特点还在于它可以减少90%形成臭氧的废气，而臭氧又是城市中最严重的污染物。
和其它的替代燃料一样，甲醇也遭到了非难。可大多数批评都建立在使用“汽油系列”的车辆不进行最简单的设计改进以可能使用甲醇燃料的基础上。例如，事实上一定体积的甲醇和同体积的汽油和柴油相比，只能提供相当于它们大约一半的能量。在其它因素相同的条件下，油箱可能要大一点和重一点，然而，由于甲醇燃料的车辆可以设计得比使用甲醇的“汽油系列”车辆还要高效，它们可能需要更少的燃料。同时，对发动机进行最简单的改进便可使用甲醇的车辆，这将对城市大气污染的迅速减轻做出贡献。
篇二：
One of the simplest and best known kinds of crystal is the ionic salt, of which a typical example is sodium chloride, or ordinary table salt. The fundamental components of an ionic salt are ions: atoms or molecules that have become electrically charged by gaining or losing one more electrons. In forming sodium chloride, for example, sodium atoms give up an electron (thereby becoming positively charged) and chlorine atoms gain an electron (thereby becoming negatively charged). The ions are attracted to one another by their opposite charges, and they stack together compactly, like tightly packed spheres.
Recently, scientists at Michigan State University created a new kind of crystal called an electride. In electrides, the anions (negative ions) are completely replaced by electrons, which are trapped in naturally formed cavities within a framework of regularly stacked cations (positive ions). Electrides are the first examples of ionic salts in which all these anionic sites are occupied solely by electrons.
Unlike other types of anions, anionic electrons do not behave as if they were simple charged spheres. In particular, because of their low mass and their tendency to interact with one another over great distances, they cannot be “pinned down” to any one location. Instead, they wander close to and among the atoms lining the cavity and interact with electrons in nearby cavities, perhaps changing places with them.
The properties of an electride depend largely on the distance between the cavities that hold trapped electrons. When the trapped electrons are far apart, they do not interact strongly, and so behave somewhat like an array of isolated negative charges. When they are closer together, they begin to display properties associated with large ensembles of identical particles. When they are still closer, the ensemble properties dominate and the electrons “delocalize”: they are no longer tightly bound within individual cavities but are more or less free to pass through the spaces within the framework of positive ions.
By synthesizing electrides from a variety of materials, one can vary the geometry of the anionic cavities and their relation to the surrounding cations. The resulting properties may make it possible for electrides to become a basis for economically useful new materials and devices. For instance, because the electrons in some electrides are very weakly bound, these crystals could be effective as photosensitive detectors, in which an impinging photon liberates an electron, resulting in a small electric current. The same weak binding could also make electrides useful in solar energy converters and as cathodes in batteries. One obstacle is the tendency of electrides to decompose through reaction with air and water. Researchers are seeking ways to increase their stability.
1. The text is primarily concerned with discussing
[A] a way to isolate electrons.
[B] the characteristics of a new kind of crystal.
[C] the structure of an ionic salt.
[D] commercial uses for electrides.
2. In the first paragraph, the author is primarily concerned with
[A] introducing a variant on the standard atomic theory.
[B] describing how chlorine atoms can become negatively charged.
[C] describing some early research at Michigan State University.
[D] providing background for the technical discussion to follow.
3. According to the text, the defining characteristic of an electride is which of the following?
[A] Its positive are of particularly low mass.
[B] Its ions possess identical electrical charges.
[C] It contains a framework of regularly stacked ions.
[D] Its negative ions consist solely of electrons.
4. It can be inferred from the text that anions behaving as “simple charged spheres” (line 2, paragraph 3) could be expected to
[A] readily lose electrons and become positively charged.
[B] move freely in and out of their cavities.
[C] respond to photons by liberating electrons.
[D] remain fixed relative to their cations.
5. With which of the following statements regarding electrides would the author most likely agree?
[A] They have proven themselves to be of great commercial value.
[B] Their future commercial value is promising but uncertain.
[C] They are interesting but of no practical value.
[D] They have commercial value mainly in solar energy applications.
[答案与考点解析]
1. 【答案】B
【考点解析】本题是一道中心主旨题。本文的中心主旨句在第二段的第一句，如果抓住了这句话并且联系每段的中心主旨句，就可得出本题的正确选项B。其实本文第二段就是在讲一种新的晶体的与众不同的“characteristics”(特点)。考生在解题时一定要首先找出全文的中心主旨句，并与上下文联系。
2. 【答案】D
【考点解析】这是一道段落关系题。从第二段到尾段是本文作者阐述其中心思想的段落。在展开中心思想之前，作者为中心思想的展开进行了铺垫(讲述一般晶体的特点)，从而为第二段到尾段的陈述(讲述一种新晶体的特点)提供明确的对比。考生在解题时一定要注意段落之间的关系。
3. 【答案】D
【考点解析】这是一道审题定位题。题干中没有给出明确的审题定位信息。破解此题需要考生平时的阅读积累，这是一道较难的题目。题干中所涉及的是“the defining characteristic of an electride”(电子晶体的特点)。在第二段作者第一次在文章中谈到了“electride”，所以其特点也应该在第二段向读者交待，故本题的答案信息来源应该在第二段。综合第二段第二、三句的内容可推导出本题的正确选项D。考生在解题时一定要具备出色的审题定位能力。
4. 【答案】D
【考点解析】本题是一道句间关系与反推题。题干中的信息以将本题的答案信息确定在第三段。根据第三段所陈述的内容进行反推可得出本题的正确选项D。在进行反推时一定要注意第一句中的“do not behave as if…”以及第二句中的“cannot be pinned down”所起的作用。考生在解题时一定要具备反推即逆向推理的能力。
5. 【答案】B
【考点解析】这是一道审题定位题。本题的题干没有提供任何审题定位的信息。但是善于阅读的考生应该知道每篇文章尾段的重要性。在本题到来之前本文的尾段还没有涉及任何一道题，故考生应该首先从尾段中寻找本题的答案信息。尾段的第二句第四句表明新的晶体在商业方面的可利用性;尾段的第五句表明这种新的晶体的不足之处。可见本题的正确选项应该是B。考生在解题时一定要对文章结构以及出题点有所认识，最好对全文有整体的把握。
[参考译文]
在各种最简单和最常见的晶体中，离子盐是其中一例，它典型的实例就是氯化钠，或普通的食盐。离子盐的基本组成成份便是离子，也就是那些由于得到或失去一个或多个电子而带有电荷的原子或分子。例如，在形成氯化钠的过程中，钠原子释放一个电子(从而带有正电荷)而氯电子得到一个电子(从而带有负电荷)。这些离子由于带有相反的电荷而相互吸引，它们紧密地堆砌在一起就象紧密挤压在一起的球体。
最近，密西根州立大学的科学家们研制出一种新的被称为电子晶体的晶体。在电子晶体中，阴离子(即带负电荷的离子)全部被电子替代，这些电子被困在自然形成的空穴中，而空穴位于规则堆砌的阳离子(即带正电荷的离子)的框架内。电子晶体是第一种阴离子空间全被电子占据的离子盐。
和其它类型的阴离子不同，作为阴离子的电子不像那些简单的带电球体。特别地，由于它们的质量很小而且有与远距离的离子进行相互作用的倾向，它们不会被固定在任何一个位置。相反，它们会到处游离，或者紧靠那些在空穴边上的原子，或者在这些原子之间游离，并且还和附近空中的电子发生相互作用，甚至于可能与它们交换位置。
电子晶体的特征很大程度上依赖于空穴间的距离，而这些空穴便是容纳被捕获电子的地方。当这些被捕获的电子相距很远时，它们之间的相互作用不强，因而在某种程度上表现为一组相互孤立的负电荷。但当它们间的距离很近时，它们便表现出一些特征来，很像大量相同离子的集合。当它们间的距离更近时，群体集合属性更占主导地位，而且电子也出现“离位”现象：它们不再被束缚于单个的空穴之上，而是或多或少地可以在正离子的构架之间穿越。
通过从不同的材料来合成电子晶体，科学家们可以改变阴离子空穴的几何结构，以及改变它们同周围阴离子之间的关系。这些随之而来的特征使得电子晶体可能成为经济实用的新材料和新设备的基础。例如，由于在某些电子晶体中，电子结合得非常微弱，从而使得这些晶体可以有效地用作光敏探测器。在这种探测器中，一束光子可以释放一个电子，从而形成一股小电流。这种结合微弱的特性同样可使电子晶体对太阳能转换器和电池的阴极很有用。可电子晶体的一个缺陷在于它易于与空气和水发生反应而分解。目前，研究人员正设法寻找提高电子晶体稳定性的方法。
篇三：
Defenders of special protective labor legislation for women often maintain that eliminating such laws would destroy the fruits of a century-long struggle for the protection of women workers. Even a brief examination of the historic practice of courts and employers would show that the fruit of such laws has been bitter: they are, in practice, more of a curse than a blessing.
Sex-defined protective laws have often been based on stereotypical assumptions concerning women’s needs and abilities and employers have frequently used them as legal excuses for discriminating against women. After the Second World War, for example, businesses and government sought to persuade women to vacate jobs in factories, thus making room in the labor force for returning veterans. The revival or passage of state laws limiting the daily or weekly work hours of women conveniently accomplished this. Employers had only to declare that overtime hours were a necessary condition of employment or promotion in their factory, and women could be quite legally fired, refused jobs, or kept at low wage levels, all in the name of “protecting” their health. By validating such laws when they are challenged by lawsuits, the courts have colluded over the years in establishing different, less advantageous employment terms for women than for men, thus reducing women’s competitiveness on the job market. At the same time, even the most well-intentioned lawmakers, courts, and employers have often been blind to the real needs of women. The lawmakers and the courts continue to permit employers to offer employee health insurance plans that cover all known human medical disabilities except those relating to pregnancy and childbirth.
Finally, labor laws protecting only special groups are often ineffective at protecting the workers who are actually in the workplace. Some chemicals, for example, pose reproductive risks for women of childbearing years: manufacturers using the chemicals comply with laws protecting women against these hazards by refusing to hire them. Thus the sex-defined legislation protects the hypothetical female worker, but has no effect whatever on the safety of any actual employee. The health risks to male employees in such industries cannot be negligible, since chemicals toxic enough to cause birth defects in fetuses or sterility in women are presumably harmful to the human metabolism. Protective laws aimed at changing production materials or techniques in order to reduce such hazards would benefit all employees without discriminating against any.
In sum, protective labor laws for women are discriminatory and do not meet their intended purpose. Legislators should recognize that women are in the work force to stay and that their needs — good health care, a decent wage, and a safe workplace — are the needs of all workers. Laws that ignore these facts violate women’s rights for equal protection in employment.
1. According to the author, which of the following resulted from the passage or revival of state laws limiting the work hours of women workers?
[A] Women workers were compelled to leave their jobs in factories.
[B] Many employers had difficulty in providing jobs for returning veterans.
[C] Many employers found it hard to attract women workers.
[D] The health of most women factory workers improved.
2. The author places the word “protecting” in quotation marks in line 9, paragraph 2 most likely in order to suggest that
[A] she is quoting the actual wording of the laws in question.
[B] the protective nature of the laws in question should not be overlooked.
[C] protecting the health of workers is important to those who support protective labor laws.
[D] the laws in question were really used to the detriment of women workers, despite being overtly protective in intent.
3. The text suggests that which of the following is a shortcoming of protective labor laws that single out a particular group of workers for protection?
[A] Such laws are often too weak to be effective at protecting the group in question.
[B] Such laws are usually drafted by legislators who do not have the best interests of workers at heart.
[C] Such laws exert no pressure on employers to eliminate hazards in the workplace.
[D] Compliance with such laws is often costly for employers and provokes lawsuits by employees claiming discrimination.
4. According to the first paragraph of the text, the author considers which of the following to be most helpful in determining the value of special protective labor legislation for women?
[A] A comparative study of patterns of work-related illnesses in states that had such laws and in states that did not.
[B] An estimate of how many women workers are in favor of such laws.
[C] An analysis of the cost to employers of complying with such laws.
[D] A study of the actual effects that such laws have had in the past on women workers.
5. The author implies that which of the following is characteristic of many employee health insurance plans?
[A] They cover all the common medical conditions affecting men, but only some of those affecting women.
[B] They lack the special provisions for women workers that proposed special labor laws for women would provide.
[C] They pay the medical costs associated with pregnancy and childbirth only for the spouses of male employees, not for female employees.
[D] They meet minimum legal requirements, but do not adequately safeguard the health of either male or female employees.
[答案与考点解析]
1. 【答案】A
【考点解析】这是一道指代词题型。考生可根据题干中的“the passage or revival of state laws limiting the work hours of women workers”将本题迅速定位在第二段的第三句，该句中的指代词“this”暗示本题的正确答案应该在第二段的第二句。这样就可以找出本题的正确答案A。考生在解题时一定要注意指代词。
2. 【答案】D
【考点解析】本题是一道标点符号题。英语作为一种语文，标点符号是非常重要的。在原文中“protecting”一词被打上引号，其含义是“所谓的保护”，作者所表达的真实含义是“没有起到保护作用的保护”。由此可见本题的正确答案应该是D。考生在解题时要重视标点符号，尤其是一些特殊的标点符号。
3. 【答案】C
【考点解析】本题是一道归纳推导题型。考生可根据题干中的“protective labor laws that single out a particular group of workers for protection”将本题的答案信息迅速确定在第三段的第一句，从第三段的内容(尤其是第三段的首尾两句)判断本题的正确答案应该是C。考生在解题时首先要具备审题定位的能力，然后要善于归纳和总结段落的细节信息。
4. 【答案】D
【考点解析】这是一道细节推导题。本题的题干以将本题的答案信息来源确定在第一段，第一段的第二句是本题正确答案D的准确信息来源也是全文的中心主旨句。考生在解题时一定要时时牢记全文的中心主旨句，尤其是在迷失解题思路时。
5. 【答案】A
【考点解析】这是一道细节推导题。根据本题题干中的“employee health insurance plans”可将本题的答案信息来源迅速确定在第二段的尾句，从第二段尾句的内容可判断本题的正确答案应该是A。考生在解题时一定要把审题定位放在第一位。
[参考译文]
妇女劳动特别保护法的辩护者经常坚持认为，废除这种法律就会破坏一个世纪以来为保护妇女工人而斗争的成果。但是，只要对法庭案例和雇主的历史作短暂回顾，就能够发现这些法律的成果是多么的令人不愉快：实际上，这种法律与其说是一件好事，不如说是一种灾祸。
以性别为界限的保护性法律通常是根据有关妇女的需要和能力的陈腐性假想为基础的，而且雇主也经常使用这些法律作为他们歧视妇女的合法借口。例如，第二次世界大战之后，企业和政府都企图说服妇女离开她们的工厂中的工作，从而为回国的老兵们在劳动力市场中空出位子。恢复或通过限制妇女每天或每周工作时间的州法律，很容易地就实现了上述的目标。雇主只需声称超时加班是在他们的工厂进行工作或提升的必要条件，这样妇女就被合法地解雇，被拒绝给予工作或者保持一种较低的工资水平，所有这些都以“保护”妇女健康的名义得以实现。当受到法律诉讼时，法庭在过去数年中一直与雇主合谋共同建立一种男女不同的，对妇女更为不利的雇佣条件，从而降低了妇女在就业市场上的竞争力。同时，即使那些最善意的立法者、法庭和雇主也经常对妇女的真实需求视而不见。法律制定者和法庭都继续允许雇主向雇员提供这样的健康保险计划，它包含了所有已知的人类疾病，但却未包括那些与怀孕和生育相关的医疗内容。
最后，那些只保护特殊群体的劳动法在保护实际工作中的工人方面经常是无效的。例如，某些化学物质会对怀孕期间的妇女造成生育上的危险。使用这些化学物品的制造商们就会遵守保护妇女避免这些危险的法律而拒绝雇佣她们。因此这种特别界定的法律保护了假设中的妇女工人，但对工人实际的任何安全问题都没有作用。在这些工厂中，对男性工人健康的危险也不能被忽略，既然那些化学毒素能导致胎儿的生育缺陷或使妇女不育，那么推而广之，其必然会对人类的新陈代谢有害。目的在于减少这种危险的保护性法律，会改变生产原料或生产技术，从而给所有雇员带来好处，而又不歧视任何一类雇员。
总而言之，为妇女制定的劳动保护法是带有歧视性的，而且并没达到它们预期的目的。立法者应该认识到，妇女是劳动力的一部分，而且她们的需求(如良好的健康保健，体面的工资收入，以及安全的工作环境)同时也是所有工人的需求。那些忽略这些事实的法律就会破坏妇女在就业中享受平等保护的权利。
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