GMAT-OG12逻辑题推理过程-WEAKEN：削弱

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1.
“Life expectancy” is the average age at death of the entire live-born population. In the middle of the nineteenth century, life expectancy in North America was 40 years, whereas now it is nearly 80 years. Thus, in those days, people must have been considered old at an age that we now consider the prime of life.

Which of the following, if true, undermines the argument above?

(A) In the middle of the nineteenth century, the population of North America was significantly smaller than it is today. （不相关：多个因素之一）
(B) Most of the gains in life expectancy in the last 150 years have come from reductions in the number of infants who die in their first year of life. （相关度大：确定）
(C) Many of the people who live to an advanced age today do so only because of medical technology that was unknown in the nineteenth century. （不相关：支持）
(D) The proportion of people who die in their seventies is significantly smaller today than is the proportion of people who die in their eighties. （不相关：支持）
(E) More people in the middle of the nineteenth century engaged regularly in vigorous physical activity than do so today. （相关度小：不确定）

分类：WEAKEN
看原文：
前提1（隐含假设）：通常寿命集中于平均寿命附近
前提2（事实）：平均寿命不同
总结论（推测）：相同年龄的衰老程度不同
找答案：指出前提的具体性，从而否定一般性
TEST：否定前提，进而否定结论
模型或要素：平均寿命 = 年龄总和 / 总人口
考点：一般情况不一般；比较，找差异

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124.
Museums that house Renaissance oil paintings typically store them in environments that are carefully kept within narrow margins of temperature and humidity to inhibit any deterioration. Laboratory tests have shown that the kind of oil paint used in these paintings actually adjusts to climatic changes quite well. If, as some museum directors believe, paint is the most sensitive substance in these works, then by relaxing the standards for temperature and humidity control, museums can reduce energy costs without risking damage to these paintings. Museums would be rash to relax those standards, however, since results of preliminary tests indicate that gesso, a compound routinely used by Renaissance artists to help paint adhere to the canvas, is unable to withstand significant variations in humidity.

In the argument above, the two portions in boldface play which of the following roles?

(A) The first is an objection that has been raised against the position taken by the argument; the second is the position taken by the argument.
(B) The first is the position taken by the argument; the second is the position that the argument calls into question.
(C) The first is a judgment that has been offered in support of the position that the argument calls into question; the second is a circumstance on which that judgment is, in part, based.
(D) The first is a judgment that has been offered in support of the position that the argument calls into question; the second is that position.
(E) The first is a claim that the argument calls into question; the second is the position taken by the argument.

分类：
看原文：
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：文物保护、变质、材料

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117.
Scientists typically do their most creative work before the age of forty. It is commonly thought that this happens because aging by itself brings about a loss of creative capacity. However, studies show that of scientists who produce highly creative work beyond the age of forty, a disproportionately large number entered their field at an older age than is usual. Since by the age of forty the large majority of scientists have been working in their field for at least fifteen years, the studies’ finding strongly suggests that the real reason why scientists over forty rarely produce highly creative work is not that they have aged but rather that scientists over forty have generally spent too long in their field.

In the argument given, the two portions in boldface play which of the following roles?

(A) The first is a claim, the accuracy of which is at issue in the argument; the second is a conclusion drawn on the basis of that claim.
(B) The first is an objection that has been raised against a position defended in the argument; the second is that position.
(C) The first is evidence that has been used to support an explanation that the argument challenges; the second is that explanation.
(D) The first is evidence that has been used to support an explanation that the argument challenges; the second is a competing explanation that the argument favors.
(E) The first provides evidence to support an explanation that the argument favors; the second is that explanation.

分类：
看原文：
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：科学家、年龄、创新

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116.
Firms adopting “profit-related-pay” (PRP) contracts pay wages at levels that vary with the firm’s profits. In the metalworking industry last year, firms with PRP contracts in place showed productivity per worker on average 13 percent higher than that of their competitors who used more traditional contracts.

If, on the basis of the evidence above, it is argued that PRP contracts increase worker productivity, which of the following, if true, would most seriously weaken that argument?

(A) Results similar to those cited for the metalworking industry have been found in other industries where PRP contracts are used. （不相关：相似结果，支持）
(B) Under PRP contracts costs other than labor costs, such as plant, machinery, and energy, make up an increased proportion of the total cost of each unit of output. （不相关：其他成本比例上升）
(C) Because introducing PRP contracts greatly changes individual workers’ relationships to the firm, negotiating the introduction of PRP contracts is complex and time-consuming. （不相关：实施难度）
(D) Many firms in the metalworking industry have modernized production equipment in the last five years, and most of these introduced PRP contracts at the same time. （相关：存在其他因素）
(E) In firms in the metalworking industry where PRP contracts are in place, the average take-home pay is 15 percent higher than it is in those firms where workers have more traditional contracts. （不相关：工资提高）

分类：
看原文：
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：薪资方案、生产率、提升
考点：找出其他因素；解释，找例外

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115.
Caterpillars of all species produce an identical hormone called “juvenile hormone” that maintains feeding behavior. Only when a caterpillar has grown to the right size for pupation to take place does a special enzyme halt the production of juvenile hormone. This enzyme can be synthesized and will, on being ingested by immature caterpillars, kill them by stopping them from feeding.

Which of the following, if true, most strongly supports the view that it would NOT be advisable to try to eradicate agricultural pests that go through a caterpillar stage by spraying croplands with the enzyme mentioned above?

(A) Most species of caterpillar are subject to some natural predation. （不相关：效果不明确）
(B) Many agricultural pests do not go through a caterpillar stage. （不相关：非目标对象）
(C) Many agriculturally beneficial insects go through a caterpillar stage. （相关：副作用）
(D) Since caterpillars of different species emerge at different times, several sprayings would be necessary. （不相关：实施过程）
(E) Although the enzyme has been synthesized in the laboratory, no large-scale production facilities exist as yet. （不相关：生产过程）

分类：
看原文：支持 + 否定 = 反对
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：生物控制、害虫
考点：找出方案副作用；方案，找效果

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114.
Guidebook writer: I have visited hotels throughout the country and have noticed that in those built before 1930 the quality of the original carpentry work is generally superior to that in hotels built afterward. Clearly carpenters working on hotels before 1930 typically worked with more skill, care, and effort than carpenters who have worked on hotels built subsequently.

Which of the following, if true, most seriously weakens the guidebook writer’s argument?

(A) The quality of original carpentry in hotels is generally far superior to the quality of original carpentry in other structures, such as houses and stores. （不相关：相同时期，其他建筑）
(B) Hotels built since 1930 can generally accommodate more guests than those built before 1930. （不相关：建筑规模不同，不明确）
(C) The materials available to carpenters working before 1930 were not significantly different in quality from the materials available to carpenters working after 1930. （不相关：建筑材料相同）
(D) The better the quality of original carpentry in a building, the less likely that building is to fall into disuse and be demolished. （相关：观察样本代表性）
(E) The average length of apprenticeship for carpenters has declined significantly since 1930. （不相关：工匠学徒期，支持）

分类：
看原文：
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：质量、耐用、样本
考点：质疑调查可靠性；调查，找疑点

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113.
The pharmaceutical industry argues that because new drugs will not be developed unless heavy development costs can be recouped in later sales, the current 20 years of protection provided by patents should be extended in the case of newly developed drugs. However, in other industries new-product development continues despite high development costs, a fact that indicates that the extension is unnecessary.

Which of the following, if true, most strongly supports the pharmaceutical industry’s argument against the challenge made above?

(A) No industries other than the pharmaceutical industry have asked for an extension of the 20-year limit on patent protection. （不相关：其他工业）
(B) Clinical trials of new drugs, which occur after the patent is granted and before the new drug can be marketed, often now take as long as 10 years to complete. （相关：研发周期长）
(C) There are several industries in which the ratio of research and development costs to revenues is higher than it is in the pharmaceutical industry. （不相关：其他工业成本高，反对）
(D) An existing patent for a drug does not legally prevent pharmaceutical companies from bringing to market alternative drugs, provided they are sufficiently dissimilar to the patented drug. （不相关：专利保护不力，反对）
(E) Much recent industrial innovation has occurred in products—for example, in the computer and electronics industries—for which patent protection is often very ineffective. （不相关：其他工业专利效果）

分类：
看原文：
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：研发成本、专利保护、时限
考点：找出其他因素；比较，找差异

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111.
The difficulty with the proposed high-speed train line is that a used plane can be bought for one-third the price of the train line, and the plane, which is just as fast, can fly anywhere. The train would be a fixed linear system, and we live in a world that is spreading out in all directions and in which consumers choose the freewheel systems (cars, buses, aircraft), which do not have fixed routes. Thus a sufficient market for the train will not exist.

Which of the following, if true, most severely weakens the argument presented above?

(A) Cars, buses, and planes require the efforts of drivers and pilots to guide them, whereas the train will be guided mechanically. （不相关：导航方式）
(B) Cars and buses are not nearly as fast as the high-speed train will be. （不相关：对比点错误）
(C) Planes are not a free-wheel system because they can fly only between airports, which are less convenient for consumers than the high-speed train’s stations would be. （相关：指出推理错误）
(D) The high-speed train line cannot use currently underutilized train stations in large cities. （不相关：其他缺点，支持）
(E) For long trips, most people prefer to fly rather than to take ground-level transportation. （不相关：飞机优点，支持）

分类：
看原文：与多个对象比较，每个对象比较点不同
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：交通工具、固定路线、火车、飞机、汽车
考点：找出类比不同；比较，找差异

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104.
Although the discount stores in Goreville’s central shopping district are expected to close within five years as a result of competition from a SpendLess discount department store that just opened, those locations will not stay vacant for long. In the five years since the opening of Colson’s, a nondiscount department store, a new store has opened at the location of every store in the shopping district that closed because it could not compete with Colson’s.

Which of the following, if true, most seriously weakens the argument?

(A) Many customers of Colson’s are expected to do less shopping there than they did before the SpendLess store opened. （不相关：顾客减少，影响不确定）
(B) Increasingly, the stores that have opened in the central shopping district since Colson’s opened have been discount stores. （相关：否定前提）
(C) At present, the central shopping district has as many stores operating in it as it ever had. （不相关：店铺未减少，支持）
(D) Over the course of the next five years, it is expected that Goreville’s population will grow at a faster rate than it has for the past several decades. （不相关：人口增加，支持）
(E) Many stores in the central shopping district sell types of merchandise that are not available at either SpendLess or Colson’s. （不相关：其他店铺）

分类：
看原文：
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：店铺、竞争
考点：找出例外情况；断言，找例外

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96.
Hotco oil burners, designed to be used in asphalt plants, are so efficient that Hotco will sell one to the Clifton Asphalt plant for no payment other than the cost savings between the total amount the asphalt plant actually paid for oil using its former burner during the last two years and the total amount it will pay for oil using the Hotco burner during the next two years. On installation, the plant will make an estimated payment, which will be adjusted after two years to equal the actual cost savings.

Which of the following, if it occurred, would constitute a disadvantage for Hotco of the plan described above?

(A) Another manufacturer’s introduction to the market of a similarly efficient burner （不相关：竞争对手）
(B) The Clifton Asphalt plant’s need for more than one new burner （不相关：更多新设备，支持）
(C) Very poor efficiency in the Clifton Asphalt plant’s old burner （不相关：旧设备效率低，支持）
(D) A decrease in the demand for asphalt （不相关：需求下降）
(E) A steady increase in the price of oil beginning soon after the new burner is installed （相关：成本增加）

分类：
看原文：
前提1（隐含假设）：
前提2（事实）：
总结论（推测）：
找答案：
TEST：
模型或要素：燃油炉、石油、成本、差额、节省
考点：找出不利因素；方案，找效果