GMAT考试中的逻辑部分，虽然每次考试形式及内容会发生相应的变化，但是思维方式还是有有相同的地方的。想要了解
1. In the first half of this year, from January to June, about three million videocassette recorders were sold. This number is only 35 percent of the total number of videocassette recorders sold last year. Therefore, total sales of videocassette recorders will almost certainly be lower for this year than they were for last year.
Which of the following, if true, most seriously weakens the conclusion above?
(A) The total number of videocassette recorders sold last year was lower than the total number sold in the year before that.
(B) Most people who are interested in owning a videocassette recorder have already purchased one.
(C) Videocassette recorders are less expensive this year than they were last year.
(D) Of the videocassette recorders sold last year, almost 60 percent were sold in January.
(E) Typically, over 70 percent of the sales of videocassette recorders made in a year occur in the months of November and December.
2. Mud from a lake on an uninhabited wooded island in northern Lake Superior contains toxic chemicals, including toxaphene, a banned pesticide for cotton that previously was manufactured and used, not in nearby regions of Canada or the northern United States, but in the southern United States. No dumping has occurred on the island. The island lake is sufficiently elevated that water from Lake Superior does not reach it.
The statements above, if true, most strongly support which of the following hypotheses?
(A) The waters of the island lake are more severely polluted than those of Lake Superior.
(B) The toxaphene was carried to the island in the atmosphere by winds.
(C) Banning chemicals such as toxaphene does not aid the natural environment.
(D) Toxaphene has adverse effects on human beings but not on other organisms.
(E) Concentrations of toxaphene in the soil of cotton-growing regions are not sufficient of be measurable.
3. Last year in the United States, women who ran for state and national offices were about as likely to win as men. However, only about fifteen percent of the candidates for these offices were women. Therefore, the reason there are so few women who win elections for these offices is not that women have difficulty winning elections but that so few women want to run.
Which of the following, if true, most seriously undermines the conclusion given?
(A) Last year the proportion of women incumbents who won reelection was smaller than the proportion of men incumbents who won reelection.
(B) Few women who run for state and national offices run against other women.
(C) Most women who have no strong desire to be politicians never run for state and national offices.
(D) The proportion of people holding local offices who are women is smaller than the proportion of people holding state and national offices who are women.
(E) Many more women than men who want to run for state and national offices do not because they cannot get adequate funding for their campaigns.
4. Samples from a ceramic vase found at a tomb in Sicily prove that the vase was manufactured in Greece. Since the occupant of the tomb died during the reign of a Sicilian ruler who lived 2,700 years ago, the location of the vase indicates that there was trade between Sicily and Greece 2,700 years ago.
Which of the following is an assumption on which the argument depends?
(A) Sicilian potters who lived during the reign of the ruler did not produce work of the same level of quality as did Greek potters.
(B) Sicilian clay that was used in the manufacture of pottery during the ruler’s reign bore little resemblance to Greek clay used to manufacture pottery at that time.
(C) At the time that the occupant of the tomb was alive, there were ships capable of transporting large quantities of manufactured goods between Sicily and Greece.
(D) The vase that was found at the Sicilian tomb was not placed there many generations later by descendants of the occupant of the tomb.
(E) The occupant of the tomb was not a member of the royal family to which the Sicilian ruler belonged.
5. In several cities, the government is going ahead with ambitious construction projects despite the high office vacancy rates in those cities. The vacant offices, though available for leasing, unfortunately do not meet the requirements for the facilities needed, such as court houses and laboratories. The government, therefore, is not guilty of any fiscal wastefulness.
Which of the following is an assumption on which the argument above depends?
(A) Adaptation of vacant office space to meet the government’s requirements, if possible, would not make leasing such office space a more cost-effective alternative to new construction.
(B) The government prefers leasing facilities to owning them in cases where the two alternatives are equally cost-effective.
(C) If facilities available for leasing come very close to meeting the government’s requirements for facilities the government needs, the government can relax its own requirements slightly and consider those facilities in compliance.
(D) The government’s construction projects would not on being completed, add to the stock of facilities available for leasing in the cities concerned.
(E) Before embarking on any major construction project, the government is required by law to establish beyond any reasonable doubt that there are no alternatives that are most cost-effective.