GMAT复习资料——逻辑重点题难题集（二）

kuaijizu

Escalating worldwide demand for corn has led to a sharp increase in the market price of corn, and corn prices are likely to remain high.  Corn is extensive used as feed for livestock, and because profit margins are tight in the livestock business, many farmers are expected to leave the business.  With fewer suppliers, meat prices will surely rise.  Nonetheless, observers expect an immediate short-term decrease in meat prices.
Which of the following, if true, most helps to justify the observers’ expectation?
A.        The increase in corn prices is due more to a decline in the supply of corn than to a growth in demand for it.
B.        Generally, farmers who are squeezed out of the livestock business send their livestock to market much earlier than they otherwise would.
C.        Some people who ate meat regularly in the past are converting to diets that include little or no meat.
D.        As meat prices rise, the number of livestock producers is likely to rise again.
E.        Livestock producers who stay in the business will start using feed other than corn more extensively than they did in the past.
答案为B。你需要知道B选项中的squeeze out of business是指退出该行业的意思，与原文说的农民leave the business一致。

kuaijizu

Which of the following most logically completes the passage?
Mastitis is an infection of the udder in cows that, although not dangerous, causes them to give poor-quality milk.  Most cases of mastitis are caused by the bacterium Staphylococcus aureus, against which antibiotics are ineffective.  However, a related bacterium, Staphylococcus simulans, quickly clears up even severe infections of S. aureus simply by displacing the bacteria.  S. simulans is nevertheless unlikely to become the preferred treatment for cases of mastitis, since ______.
A.        certain dangerous bacteria that normally cannot take hold can do so in the presence of S. simulans
B.        the current resistance of S. aureus to antibiotics derives in part from a past pattern of overuse of those antibiotics
C.        the milk from cows infected with S. aureus is generally not of such poor quality as to be entirely unusable
D.        careful farming practice can reduce the incidence of mastitis to a minimum
E.        the only symptom of mild cases of mastitis is the deterioration in the quality of the milk produced
答案为A。你需要明白A选项中的cannot take hold大概是指“在体内寄生”的意思。（合理推测猜测）

kuaijizu

Environmental organizations want to preserve the land surrounding the Wilgrinn Wilderness Area from residential development.  They plan to do this by purchasing that land from the farmers who own it.  That plan is ill-conceived:  if the farmers did sell their land, they would sell it to the highest bidder, and developers would outbid any other bidders.  On the other hand, these farmers will never actually sell any of the land, provided that farming it remains viable.  But farming will not remain viable if the farms are left unmodernized, and most of the farmers lack the financial resources modernization requires.  And that is exactly why a more sensible preservation strategy would be to assist the farmers to modernize their farms to the extent needed to maintain viability.
In the argument as a whole, the two boldface proportions play which of the following roles?
A.        The first presents a goal that the argument rejects as ill-conceived; the second is evidence that is presented as grounds for that rejection.
B.        The first presents a goal that the argument concludes cannot be attained; the second is a reason offered in support of that conclusion.
C.        The first presents a goal that the argument concludes can be attained; the second is a judgment disputing that conclusion.
D.        The first presents a goal, strategies for achieving which are being evaluated in the argument; the second is a judgment providing a basis for the argument’s advocacy of a particular strategy.
E.        The first presents a goal that the argument endorses; the second presents a situation that the argument contends must be changed if that goal is to be met in the foreseeable future.
答案为D。本题需要阅读原文。D像中的particular strategy指全文最后一句话的assist the farmers to modernize ….

kuaijizu

A survey of entrepreneurs who started companies last year shows that while virtually all did substantial preparatory research and planning, only half used that work to produce a formal business plan.  Since, on average, the entrepreneurs without formal plans secured the capital they needed in half the time of those with plans, these survey results indicate that, in general, formal plans did not help the entrepreneurs who produced them to secure the capital they needed.
Which of the following, if true, most seriously weakens the argument?
A.        Companies started by entrepreneurs who had used formal business plans to attract investment were on the whole as profitable in their first year as were companies started by entrepreneurs who had not produced such plans.
B.        In surveys of entrepreneurs who have attempted without success to raise sufficient capital, more than half of the respondents indicate that they have produced a formal business plan.
C.        Among the entrepreneurs surveyed, those who did not produce formal business plans sought and received a much larger proportion of their capital from investors with whom they had a long-standing business relationship.
D.        The entrepreneurs surveyed who did not produce a formal business plan spent nearly as much time doing preparatory research and planning as the entrepreneurs who produced plans.
E.        The entrepreneurs who produced business plans generally reported later that the process of writing the plan had increased their confidence that their company would succeed.
答案选B。选项C错误的原因是它只说明了research and planning很重要，而没有证明formal business plan很重要。

kuaijizu

Lawmaker: Raising taxes is not the only means of reducing government debt. The government’s stockpile of helium is worth 25 percent more, at current market prices, than the debt accumulated in acquiring and storing it. Therefore, by selling the helium, the government can not only pay off that debt but reduce its overall debt as well.
Which of the following is an assumption on which the argument depends?
A.        The government has no current need for helium.
B.        Twenty-five percent of the debt the government has accumulated in stockpiling helium is not an insignificant portion of the government’s total debt.
C.        It is not in the lawmaker’s interest to advocate raising taxes as a means of reducing government debt.
D.        Attempts to sell the government’s helium will not depress the market price of helium by more than 25 percent.
E.        The government will not incur any costs in closing its facilities for stockpiling helium.
答案选D。题目结论讨论的是pay debt的事情，故选项A错。Not incur any costs太绝对，故选项E错误。

kuaijizu

A medieval manuscript called L contains all eighteen extant tragedies by the Greek playwright Euripides. Of these, ten called the “select plays,” are accompanied in L by ancient commentaries and also appear in other medieval manuscripts; this group includes some of Euripides’ best-known works, including the Medea. The other eight, which appear in alphabetical order, without commentary. The Electra is one of the alphabeticals.
Which of the following can be reliably concluded on the basis of the Statements given?
A.        Only Euripides’ best-known works are accompanied by ancient commentaries in extant medieval manuscripts.
B.        The select plays are accompanied by ancient commentaries because they were the best known of Euripides’ works.
C.        No commentaries were written about Euripides’ Electra in ancient times.
D.        Euripides’ Medea never appears in medieval manuscripts unaccompanied by ancient commentary.
E.        Euripides’ Electra does not appear accompanied by a commentary in any extant medieval manuscript.
答案选E。仔细阅读全文倒数第二句话，其意思是说L合集中不包括Electra的commentary，但不代表其他地方没有，故C错。

kuaijizu

In order to raise revenue, the federal government planned a tax amnesty program that allows tax delinquents to pay all owed tax without added financial penalty. However, economists projected that the federal government would collect a far lower percentage of total tax owed by delinquents than did state governments implementing similar programs.
Which of the following, if true, would most contribute to an explanation of the economists’ projections?
A.        Tax amnesty programs are only successful if they are widely publicized.
B.        Most people who honestly pay their state tax are equally honest in paying their federal tax.
C.        Although federal tax delinquents usually must pay high financial penalties, the states require far lower financial penalties.
D.        The state tax rate varies considerably from state to state, but the federal tax is levied according to laws which apply to citizens of all the states.
E.        Unlike most federal tax delinquents, most state tax delinquents fail to pay state tax because of an oversight rather than a decision not to pay.
答案选E。选项C错误的原因是如果该情况真实，则此次联邦政府采取的免除penalty政策将会很有效果，即削弱了原文结论。

kuaijizu

Because it was long thought that few people would watch lengthy televised political messages, most televised political advertisements, like commercial advertisements, took the form of short messages.  Last year, however, one candidate produced a half-hour-long advertisement.  At the beginning of the half-hour slot a substantial portion of the viewing public had tuned in to that station.  Clearly, then, many more people are interested in lengthy televised political messages than was previously thought.
Which of the following, if true, most seriously weakens the argument?
A. The candidate who produced the half-hour-long advertisement did not win election at the polls.
B. The half-hour-long advertisement was widely publicized before it was broadcast.
C. The half-hour-long advertisement was aired during a time slot normally taken by one of the most popular prime-time shows.
D. Most short political advertisements are aired during a wide range of programs in order to reach a broad spectrum of viewers.
E. In general a regular-length television program that features debate about current political issues depends for its appeal on the personal qualities of the program's moderator.
答案选C。本题的关键是看清原文中说的At the beginning of the half-hour slot中的beginning。

kuaijizu

Columnist:  People should avoid using a certain artificial fat that has been touted as a resource for those whose medical advisers have advised them to reduce their fat intake.  Although the artificial fat, which can be used in place of fat in food preparation, has none of the negative health effects of fat, it does have a serious drawback: it absorbs certain essential vitamins, thereby preventing them from being used by the body.
In evaluating the columnist's position, it would be most useful to determine which of the following?
(A) Whether increasing one's intake of the vitamins can compensate for the effects of the artificial fat
(B) Whether the vitamins that the artificial fat absorbs are present in foods that contain the fat
(C) Whether having an extremely low fat intake for an extended period can endanger the health
(D) Whether there are any foods that cannot be prepared using the artificial fat as a substitute for other fats
(E) Whether people are generally able to detect differences in taste between foods prepared using the artificial fat and foods that are similar except for the use of other fats
答案为A。B选项错误的原因是根据原文最后一句话，即使食物中有vitamin，由于人工fat的存在，该vitamin也无法被人体吸收。

kuaijizu

A shortage of orders for Manto Aircraft’s airliners has led analysts to predict that the manufacturer will have to lay off workers, the new order that Consolidated Airlines has just made for 20 of Manto’s model TX jets does not provide a reason for the analysts to revise their predictions, because simultaneously with its new order, Consolidated Airlines canceled its existing order for an equal number of manto’s larger, more expensive model Z jets.
Which of the following, if true, most seriously weakens the argument?
A.        Manto relies more heavily on outside subcontractors to provide the labor to manufacture the model Z than it does the model TX
B.        The Manto employees who currently work to manufacture the model Z are not proficient at manufacturing the model TX
C.        Manto includes all required maintenance work for the first five years in the price of each jet it sells
D.        Manto has had to lay off workers several times within the past ten years but has typically rehired many of the workers when it subsequently received new orders
E.        A large number of the airliners in consolidated fleet are at the beginning of their expected service life
答案为A。本题只是题干比较复杂，题目本身难度并不是很大（注意看清原文中model TX和model Z这两个不同机型的叙述）。