2017年考研英语阅读理解专项试题及答案
[答案与考点解析]
1. 【答案】C
【考点解析】本题是一道中心主旨题。本文的中心主旨句是首段的第二句,该句中的“these materials”指的就是首段第一句中的“amorphous metallic alloys or glassy metals”。可见本题的正确答案应该是C。考生一定要知道:破解中心主旨题的关键在于抓住全文的中心主旨句。
2. 【答案】C
【考点解析】本题是一道审题定位题。根据题干中的“prospects”(前景)可将本题的答案信息迅速确定在尾段,因为尾段首句中的“promising”(有前途的)暗示本段讲某种事物的前景或未来。本题的确切答案信息来源在尾段的最后一句,该句中的“that is likely to be overcome”暗示本题的正确答案是C。考生在解题时一定要具备迅速地审题定位能力,还要具备理解原文深层含义的能力。
3. 【答案】D
【考点解析】这是一道细节推导题。根据题干中的“crystalline structure”可将本题的答案迅速确定在第二段的首句,该句中的“depends on”和题干中的“determines”相互呼应。通过仔细理解第二段的首句可推导出本题的正确选项是D。请考生注意原文中“composition”和选项中“consists of”的转换。考生在解题时一定要具备细节推导能力,不能只停留于文字的表面含义。
4. 【答案】D
【考点解析】这是一道细节推导题。根据题干中的“the structure of liquid metals and the structure of glassy metals”可将本题的答案信息来源迅速确定在第三段的首句。该句中的“similar”一词暗示选项D是正确答案。考生在解题时应重视对立对比关系。
5. 【答案】C
【考点解析】本题是一道总结归纳信息并进行引申推导题型。从本题题干中的“molten nonmetallic glasses”可断定本题的答案信息在本文第二段,因为该句中包含有题干中的核心词语“molten nonmetallic glasses”。我们需要归纳和总结本段的每一句话,尤其是第三、四句的内容,另外本段尾句的含义为推导(infer)出本题的正确选项C起到至关重要的作用。考生在破解此类题型时一定要注意首先归纳和总结原文中相应出题点的全面信息,更要注意逻辑推导的能力。
[参考译文]
材料科学家和固体物理学家的深入研究已促进了一种固体物质的出现,这类固体被称为非晶体金属合金,也就是玻璃金属。理论和应用研究者对这些材料的结构特性的兴趣正与日俱增。
当一种熔化的金属和金属合金冷却成固体时,依赖于特定的合金成份将形成各种晶体结构。相比之下,熔化的非金属、玻璃类材料在冷却后将不会形成晶体结构,而是保留一点类似于液体的非晶体结构,在室温条件下,两类材料的自然的长期倾向都形成了晶体结构。它们之间的不同在于动态性,即形成晶体结构的速度。这种动态性受下述两种因素控制:化学结合的性质和分子之间相互运动的自由程度。由此,对金属而言,动态历程有利于晶体结构的快速形成;而对非金属来说,这种形成速度非常慢,以至于任何自然冷却速度都足以形成一种非晶体结构。要想形成玻璃金属,熔化的金属必须以极快的速度冷却,以抑制晶体的形成。
人们认为玻璃金属的结构与液态金属的结构类似。创建这种液体结构模型的第一次尝试是已故的伦敦大学的J. D.鲍纳尔进行的,他将坚硬的球体尽可能多地填塞进一个橡胶容器中,以便得到一种最大可能的密度。这个密度结果以及随机填塞结构以后便成为试图建立玻璃金属结构模型的基础。
基于鲍纳尔模型,由合成金属的成份组成对合金密度的计算结果与实验测得的结果相当地吻合,当然一些细微的差异仍然存在。实验结果是通过测量由一种重金属和类金属组成的合金得到的,如钯和硅的合金,或铁磷和碳组成的合金。实际的合金和鲍纳尔模型所用的球体之间的差别在于合金的成份有不同的体积大小,因此,基于两种大小的球体的模型更适合于两类物质的合金。合金中非金属的小原子可能填进由大原子随机填塞形成的紧密结构中。
玻璃金属最有前景的一个特征是高强度与高延伸性的结合。在常见的晶体材料中,这两种特性一般是成反比的,但人们渴望它们同时存在。在实际用途中可能还有一个问题急待解决,即当玻璃金属在相对的低温下慢慢加热时,它会逐渐变为晶体结构。
篇三:
The complications frequently accompanying diabetes, such as impairment of vision and of kidney function, are now thought to result from the lack of continuous control of blood glucose concentrations. The healthy pancreas, in response to increases in blood glucose concentration, releases small quantities of insulin throughout the day and thereby maintains the concentration within physiological limits (nomoglycemia). But the diabetic generally receives only one large dose daily. The diabetic’s blood glucose concentration can thus fluctuate greatly during the interval between doses, and it has been suggested that the complication result from the periods of high concentrations of blood glucose (hyperglycemia). Many investigators thus believe that restoration of normoglycemia might halt the progression of such complications and perhaps even reverse them.
There are three primary techniques that have been investigated for restoration of normoglycemia. They are: transplantation of whole, healthy pancreases; transplantation of islets of Langerthan, that portion of the pancreas that actually secretes insulin, and implantation of artificial pancreases. There has, in fact been a great deal of success in the development of these techniques and each seems, on the whole, promising. Nonetheless, it will undoubtedly be many years before any one of them is accepted as a treatment for diabetes.
To many people, the obvious approach would seem to be simply to transplant pancreases from cadavers in the same manner that kidneys and other organs are routinely transplanted. That was the rationale in 1966 when the first recorded pancreas was performed. Between 1960 and 1975, there were forty-six pancreas transplants in forty-five other patients in the United States and five other countries. But only one of these patients is still alive with a functioning graft and surgeons have found that the procedure is not simple as they once thought.
The surviving patient has required no insulin since the operation. Another patient survived 638 days without requiring insulin. And one patient survived a transplantation for more than a year, but died when he chose not to take immunosuppressive drugs. These results, though meager, suggest that the procedure has the potential for success.
The rest of the patients, however, either rejected the transplant or died within a short period. There does not appear to be any technical problem with the procedure. Rather, most of the patients were already so severely debilitated by the complications of diabetes that they could not withstand the surgery and the immunosuppressive regimen required to prevent rejection. More than half of the patients, furthermore, also required a kidney transplant. Most investigators now agree that the simultaneous transplantation of both organs is too great a shock to the patient and greatly increases the total risk.
1. Which of the following best states one of the main conclusions of the text?
[A] Although the techniques for pancreas transplants appear to be theoretically correct, there are problems that must be solved before the operation can be used as a treatment for diabetes.
[B] Although the techniques for pancreas transplants are still being developed, the experimental results show that the operation will be a successful treatment for diabetes in the near future.
[C] Although pancreas transplants are reliable, many diabetics are reluctant to undergo the operation because of the side effects of immunosuppressive drugs.
[D] Although pancreas transplants alone are not generally successful, the operation can be used in conjunction with other procedures to treat diabetes.
2. According to the text, widely spaced doses of insulin can cause
[A] reversal of normal kidney function.
[B] delay in the onset of diabetes.
[C] radical changes in the concentration of blood glucose.
[D] restoration of normoglycemia.
3. According to the text, a periodic high concentration of blood glucose in diabetics is a possible cause of
[A] deterioration of the pancreas.
[B] damage to the eyes and kidneys.
[C] rejection of transplanted organs.
[D] inadequate secretion of insulin.
4. It can be inferred from the text that one of the important contributing causes of the failure of most pancreas transplants has been the
[A] reluctance of patients to cooperate with physicians.
[B] imperfect techniques used in the operation.
[C] scarcity of immunosuppressive drugs.
[D] weakened condition of the patients.
5. The text suggests that the author considers the data concerning the success of pancreas transplants to be
[A] invalid.
[B] indirect.
[C] inaccurate.
[D] insufficient.
[答案与考点解析]
1. 【答案】A
【考点解析】本题是一道审题定位题。本题的题干比较奇怪,没有明确指出本题答案信息在原文中的确切位置。在大多数情况下,考生会迷失解题思路。我们一再重申:考生在迷失解题思路时一定要多想一想全文的中心主旨句,以及各段的主题句。本文的中心主旨句是第二段的尾句,本题的正确选项A恰恰是来自于本句。这再次说明我们在迷失解题思路时应该首先想到全文的中心主旨句或每段的主题句。
2. 【答案】C
【考点解析】这是一道细节推导题。通过本题题干中的“widely spaced doses of insulin”可将本题的答案信息来源确定在首段的第三、四句。因为这两句话提到了“doses of insulin”。通过仔细阅读和理解第三、四句,就可推导出本题的正确选项C。考生在解题时一定要善于理解和把握题干和原文所进行的同义词替换。
3. 【答案】B
【考点解析】这是一道句间关系题。通过题干中的“periodic high concentration”可将本题的答案信息来源迅速确定在第一段的第四句。通过仔细阅读和理解第四句,尤其是把第四句中的“complication”和第一句中的“complications”进行连贯的理解,就可推导出本题的正确选项B。考生在解题时要善于发现和理解句子之间的关系。
4. 【答案】D
【考点解析】这是一道细节推导题。通过题干中的“failure”一词可推断本题的正确答案信息在倒数第二段尾句的前后,因为该句所谈论的中心话题是“success”。又根据题干中的“most”一词将本题的答案信息确定在尾段的第三句,因为该句中含有“most”一词。通过阅读和理解尾段第三句,可推导出本题的正确答案是D。考生在解题时要注意灵活理解题干和原文所表达的内容,千万不能生硬地进行理解。
5. 【答案】D
【考点解析】本文是一道词汇理解题。本题题干中的“success”将本题的答案信息来源确定在倒数第二段的尾句。该句中的“meager”(不足的,贫乏的)暗示本题的正确选项是D。考生在解题时一定要对关键词加以重视并进行合理的推断。
[参考译文]
通常与糖尿病相伴的并发症,如视力和肾功能的损害,现在被认为是由于无法连续控制血液中的葡萄糖浓度所导致的。健康的胰脏,在血糖浓度增加时,会在整个白天不断地释放出少量的胰岛素,从而使血糖浓度维持在生理限度之内(正常血糖量)。但是糖尿病患者一般是每天得到一次大剂量胰岛素的注射。这样在两次注射之间,糖尿病患者的血糖浓度会发生很大波动,而且目前已被指出,并发症可能就是源于这些高血糖浓度时期(高血糖)。因此,许多研究人员相信,恢复正常的血糖浓度或许能阻止这些并发症的发展,并进而可能减轻并发症。
为了恢复正常的血糖浓度,已对三种主要的技术进行了研究。它们分别是:健康胰脏的整个移植;胰岛部分的移植,胰岛是胰腺中实际分泌胰岛素的部分;以及人造腺的移植。事实上,这些技术的发展都获得了成功,而且从整体上讲,每种技术都大有希望。然而,毫无疑问地,在任何一种技术被接受用作糖尿病患者的治疗手段之前,还会有很多年的时间。
对多数人而言,显而易见的方法看来可能是从尸体中移植胰腺,就象移植肾脏和其它器官那样。这便是1966年第一例胰腺移植手术的理论基础。在1966年至1975年间,在美国和另外五个国家,共有45名其它病人进行了46例胰腺移植手术。但目前,只有其中一个病人尚在人世,而且移植的胰腺功能健全。因此,手术医生们发现,手术过程并不像他们先前想象的那么简单。
幸存的病人从那次手术之后不再需要注射胰岛素。另一个病人在不需要注射胰岛素的情况下活了638天。还有一名病人在移植之后存活了一年,但他决定不服用免疫药物之后就死去了。这些结果,尽管为数不多,可也表明了手术过程有潜在成功的可能。
然而,其余的病人或者出现排异反应,或者在很短一段时期后死去。在手术过程中,看起来是不存在任何技术问题的。不过,大多数的病人都由于糖尿病的并发病已经很衰弱,以至于无法经受手术和为防止排异反应所需的免疫抑制疗程。另外,一大半病人还需要进行肾脏移植。目前,多数研究人员都认为同时移植两个器官对病人自身系统影响太大,而且极大地增加了整体的风险。
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