帶答案的邏輯講義

1、.GMAT邏輯 講義高智威目 錄歸納題 1削弱題 12加強題 37假設(shè)題 54解釋題 73填空題 83句子作用題 94評價題 1061. 歸納題標(biāo)志詞：做題方法：1.2. 注意事項：1.2. 例題1. Meteorite explosions in the Earths atmosphere as large as the one that destroyed forests in Siberia, with approximately the force of a twelve-megaton nuclear blast, occur about once a century. The re

2、sponse of highly automated systems controlled by complex computer programs to unexpected circumstances is unpredictable.Which of the following conclusions can most properly be drawn, if the statements above are true, about a highly automated nuclear-missile defense system controlled by a complex com

3、puter program?A. Within a century after its construction, the system would react inappropriately and might accidentally start a nuclear war.B. The system would be destroyed if an explosion of a large meteorite occurred in the Earths atmosphere.C. It would be impossible for the system to distinguish

4、the explosion of a large meteorite from the explosion of a nuclear weapon.D. Whether the system would respond inappropriately to the explosion of a large meteorite would depend on the location of the blast.E. It is not certain what the systems response to the explosion of a large meteorite would be,

5、 if its designers did not plan for such a contingency.2. The fewer restrictions there are on the advertising of legal services, the more lawyers there are who advertise their services, and the lawyers who advertise a specific service usually charge less for that service than lawyers who do not adver

6、tise. Therefore, if the state removes any of its current restrictions, such as the one against advertisements that do not specify fee arrangements, overall consumer legal costs will be lower than if the state retains its current restrictions.If the statements in the passage are true, which of the fo

7、llowing must be true?A. Some lawyers who now advertise will charge more for specific services if they do not have to specify fee arrangements in the advertisements.B. More consumers will use legal services if there are fewer restrictions on the advertising of legal service.C. If the restriction agai

8、nst advertisements that do not specify fee arrangements is removed, more lawyers will advertise their services.D. If more lawyers advertise lower prices for specific services, some lawyers who do not advertise will also charge less than they currently charge for those services.E. If the only restric

9、tions on the advertising of legal services were those that apply to every type of advertising, most lawyers would advertise their services.3. Rural households have more purchasing power than do urban or suburban households at the same income level, since some of the income urban and suburban househo

10、lds use for food and shelter can be used by rural households for other needs.Which of the following inferences is best supported by the statement made above?A. The average rural household includes more people than does the average urban or suburban household. B. Rural households have lower food and

11、housing costs than do either urban or suburban households. C. Suburban households generally have more purchasing power than do either rural or urban households. D. The median income of urban and suburban households is generally higher than that of rural households. E. All three types of households s

12、pend more of their income on housing than on all other purchases combined.4. When a polygraph test is judged inconclusive, this is no reflection on the examinee. Rather, such a judgment means that the test has failed to show whether the examinee was truthful or untruthful. Nevertheless, employers wi

13、ll sometimes refuse to hire a job applicant because of an inconclusive polygraph test result.Which of the following conclusions can most properly be drawn from the information above?A. Most examinees with inconclusive polygraph test results are in fact untruthful.B. Polygraph tests should not be use

14、d by employers in the consideration of job applicants. C. An inconclusive polygraph test result is sometimes unfairly held against the examinee. D. A polygraph test indicating that an examinee is untruthful can sometimes be mistaken.E. Some employers have refused to consider the results of polygraph

15、 tests when evaluating job applicants.5. (Z1) That the application of new technology can increase the productivity of existing coal mines is demonstrated by the case of Tribnias coal industry. Coal output per miner in Tribnia is double what it was five years ago, even though no new mines have opened

16、.Which of the following can be properly concluded from the statement about coal output per miner in the passage?A.If the number of miners working in Tribnian coal mines has remained constant in the past five years, Tribnias total coal production has doubled in that period of time.B.Any individual Tr

17、ibnian coal mine that achieved an increase in overall output in the past five years has also experienced an increase in output per miner.C.If any new coal mines had opened in Tribnia in the past five years, then the increase in output per miner would have been even greater than it actually was.D.If

18、any individual Tribnian coal mine has not increased its output per miner in the past five years, then that mines overall output has declined or remained constant.E.In Tribnia the cost of producing a given quantity of coal has declined over the past five years.6. (Z2-20) Shipping Clerk: The five spec

19、ially ordered shipments sent out last week were sent out on Thursday. Last week, all of the shipments that were sent out on Friday consisted entirely of building supplies, and the shipping department then closed for the weekend. Four shipments were sent to Truax Construction last week, only three of

20、 which consisted of building supplies.If the shipping clerks statements are true, which of the following must also be true?A.At least one of the shipments sent to Truax Construction last week was specially ordered.B.At least one of last weeks specially ordered shipments did not consist of building s

21、upplies.C.At least one of the shipments sent to Truax Construction was not sent out on Thursday of last week.D.At least one of the shipments that were sent out on Friday of last week was sent to Truax Construction.E.At least one of the shipments sent to Truax Construction last week was sent out befo

22、re Friday.7. (Z2-30) Although most smoking-related illnesses are caused by inhaling the tar in tobacco smoke, it is addiction to nicotine that prevents most smokers from quitting. In an effort to decrease the incidence of smoking-related illnesses, lawmakers in Sandonia plan to reduce the average qu

23、antity of nicotine per cigarette by half over the next five years. Unfortunately, smokers who are already addicted to nicotine tend to react to such reductions by smoking correspondingly more cigarettes.The information above most strongly supports which of the following predictions about the effects

24、 of implementing the Sandonian governments plan?A.The average quantity of tar inhaled by Sandonian smokers who are currently addicted to nicotine will probably not decrease during the next five years.B.Sandonian smokers who are not already addicted to nicotine will probably also begin to smoke more

25、cigarettes during the next five years than they had previously.C.The annual number of Sandonian smokers developing smoking-related illnesses will probably decrease during the next five years.D.The proportion of Sandonians attempting to quit smoking who succeed in that attempt will probably decrease

26、during the next five years.E.The number of Sandonians who quit smoking during the next five years will probably exceed the number who quit during the last five years.8. (Z3-32) From 1980 to 1989, total consumption of fish in the country of Jurania increased by 4.5 percent, and total consumption of p

27、oultry products there increased by 9.0 percent. During the same period, the population of Jurania increased by 6 percent, in part due to immigration to Jurania from other countries in the region.If the statements above are true, which of the following must also be true on the basis of them?A. During

28、 the 1980s in Jurania, profits of wholesale distributors of poultry products increased at a greater rate than did profits of wholesale distributors of fish. B. For people who immigrated to Jurania during the 1980s, fish was less likely to be a major part of their diet than was poultry.C. In 1989 Jur

29、anians consumed twice as much poultry as fish.D. For a significant proportion of Juranias population, both fish and poultry products were a regular part of their diet during the 1980s.E. Per capita consumption of fish in Jurania was lower in 1989 than in 1980.9. A company's two divisions perform

30、ed with remarkable consistency over the past three years: in each of those years, the pharmaceuticals division has accounted for roughly 20 percent of dollar sales and 40 percent of profits, and the chemicals division for the balance.Regarding the past three years, which of the following can properl

31、y be inferred from the statement above?(A)Total dollar sales for each of the company's divisions have remained roughly constant.(B)The pharmaceuticals division has faced stiffer competition in its markets than has the chemicals division.(C)The chemicals division has realized lower profits per do

32、llar of sales than has the pharmaceuticals division.(D)The product mix offered by each of the company's divisions has remained unchanged.(E)Highly profitable products accounted for a higher percentage of the chemicals division's sales than of the pharmaceuticals division's.10.(Z6-40) Fro

33、m 1973 to 1976, total United States consumption of cigarettes increased 3.4 percent, and total sales of chewing tobacco rose 18.0 percent. During the same period, total United States population increased 5.0 percent.If the statements above are true, which of the following conclusions can be properly

34、 drawn?A.United States manufacturers of tobacco products had higher profits in 1976 than in 1973.B.Per capita consumption of cigarettes in the United States was lower in 1976 than in 1973.C.The proportion of nonsmokers in the United States population dropped slightly between 1973 and 1976.D.United S

35、tates manufacturers of tobacco products realize a lower profit on cigarettes than on chewing tobacco.E.A large percentage of United States smokers switched from cigarettes to chewing tobacco between 1973 and 1976.例題答案：ECBCA EAECB練習(xí)題：1. Advertisement: Today's customers expect high quality. Every

36、advance in the quality of manufactured products raises customer expectations. The company that is satisfied with the current quality of its products will soon find that its customers are not. At MegaCorp, meeting or exceeding customer expectations is our goal.Which of the following must be true on t

37、he basis of the statements in the advertisement above?(A)MegaCorp's competitors will succeed in attracting customers only if those competitors adopt MegaCorp's goal as their own.(B)A company that does not correctly anticipate the expectations of its customers is certain to fail in advancing

38、the quality of its products.(C)MegaCorp's goal is possible to meet only if continuing advances in product quality are possible.(D)If a company becomes satisfied with the quality of its products, then the quality of its products is sure to decline.(E)MegaCorp's customers are currently satisfi

39、ed with the quality of its products.2. Social scientists are underrepresented on the advisory councils of the National Institutes of Health (NIH). Since these councils advise NIH directors and recommend policy, the underrepresentation of social scientists results in a relative lack of NIH financial

40、support for research in the social sciences.If the statements above are correct, they most strongly support which of the following?(A)A significant increase in the size of NIH advisory councils would be required in order to increase the representation of social scientists on these councils.(B)A sign

41、ificant increase in the representation of social scientists on NIH advisory councils would result in an increase in NIH funding for social science research.(C)A significant increase in funding for social science research would result in improved policy' recommendations to NIH directors.(D)A sign

42、ificant increase in funding for the training of social scientists would result in an increase in the number of social scientists on NIH advisory councils.(E)A significant increase in the representation of social scientists on NIH advisory councils would have to precede any increase in the number of

43、NIH directors who are social scientists.3.(Z7-13)Fact: Asthma, a bronchial condition, is much less common ailment than hay fever, an allergic inflammation of the nasal passages.Fact: over 95 percent of people who have asthma also suffer from hay fever.If the information given as facts above is true,

44、 which of the following must also be true?A.Hay fever is a prerequisite for the development of asthmaB.Asthma is a prerequisite for the development of hay feverC.Those who have neither hay fever nor asthma comprise less than 5 percent of the total populationD.The number of people who have both of th

45、ese ailments is greater than the number of people who have only one of them E.The percentage of people suffering from hay fever who also have asthma is lower than 95 percent.4. (Z8-30)The quality of unrefined olive oil is not actually defined in terms of acidity, yet extensive tests have shown that

46、the less free oleic acid an unrefined olive oil contains per liter, the higher its quality. The proportion of free oleic acid that an olive oil contains is an accurate measure of the oils acidity.If the statements above are all true, which of the following conclusions is best supported by them?A.Whe

47、n an olive oil is refined, the concentration of oleic acid in the oil is reduced.B.The quality of an unrefined olive oil can be determined only by accurately measuring its acidity.C.If an unrefined olive oil is intermediate in acidity between two other unrefined olive oils, it will also be intermedi

48、ate between them in quality.D.Free oleic acid is the only acid that unrefined olive oil contains.E.People who judge the quality of unrefined olive oils actually judge those oils by their acidity, which the judges can taste.5.(Z11-23)Macrophages are cells that play a role in the response of the immun

49、e system of mice and other mammals to invasive organisms such as bacteria. Unlike other mice, mice that are genetically incapable of making these particular cells do not show elevated levels of nitrates when infected with bacteria.The statements above, if true, provide the most support for which of

50、the following conclusions?A.Mice that are unable either to make macrophages or to make them in sufficient numbers will protect themselves from bacterial infections in some other way.B.Mice that show elevated levels of nitrates can easily fight off most types of bacterial infections.C.In mice, macrop

51、hages play a role in the production of nitrates or inhibit a process by which nitrates are broken down or otherwise eliminated.D.When a healthy mouse becomes infected with an invasive organism, the number of macrophages in the mouses body decreases.E.Injections of nitrates into mice that lack macrop

52、hages will not enhance the ability of these animals immune systems to fight off infection.6.(Z13-30) The percentage of households with an annual income of more than $40,000 is higher in Merton county than in any other county. However, the percentage of households with an annual income of $60,000 or

53、more is highest in Sommer county.If the statements above are true, which of the following can properly be concluded on the basis of them?A.No households in Merton county has an annul income of $60,000 or moreB.Some households in Merton county have an annual income between $40,000 and $60,000C.The nu

54、mber of households with an annual income of more than $40,000 is greater in Merton than in Sommer county.D.Average annual household income is higher in Sommer than in Merton county.E.The percentage of households with an annual income of $80,000 is higher in Sommer than in Merton county.7. Among the

55、more effective kinds of publicity that publishers can get for a new book is to have excerpts of it published in a high-circulation magazine soon before the book is published. The benefits of such excerption include not only a sure increase in sales but also a fee paid by the magazine to the book'

56、;s publisher.Which of the following conclusions is best supported by the information above?(A)The number of people for whom seeing an excerpt of a book in a magazine provides an adequate substitute for reading the whole book is smaller than the number for whom the excerpt stimulates a desire to read

57、 the book.(B)Because the financial advantage of excerpting a new book in a magazine usually accrues to the book's publisher, magazine editors are unwilling to publish excerpts from new books.(C)In calculating the total number of copies that a book has sold, publishers include sales of copies of magazines that featured an excerpt of the book.(D)The effectiveness of having excerpts of a book published in a magazine, measured in terms of increased sales of a book, is proportional to the circulation of the magazine in which the excerpts are published.(E)Books that are suitable for ex