2013年GMAT逻辑推理模拟训练（23）

　　25 Minutes 16 Questions

　　1. The chanterelle, a type of wild mushroom, grows beneath host trees such as the Douglas fir, which provide it with necessary sugars. The underground filaments of chanterelles, which extract the sugars, in turn provide nutrients and water for their hosts. Because of this mutually beneficial relationship, harvesting the chanterelles growing beneath a Douglas fir seriously endangers the tree.

　　Which of the following, if true, casts the most doubt on the conclusion drawn above?

　　(A) The number of wild mushrooms harvested has increased in recent years.

　　(B) Chanterelles grow not only beneath Douglas firs but also beneath other host trees.

　　(C) Many types of wild mushrooms are found only in forests and cannot easily be grown elsewhere.

　　(D) The harvesting of wild mushrooms stimulates future growth of those mushrooms.(D)

　　(E) Young Douglas fir seedlings die without the nutrients and water provided by chanterelle filaments.

　　2. The reason much refrigerated food spoils is that it ends up out of sight at the back of the shelf. So why not have round shelves that rotate? Because such rotating shelves would have just the same sort of drawback, since things would fall off the shelves’ edges into the rear corners.

　　Which of the following is presupposed in the argument against introducing rotating shelves?

　　(A) Refrigerators would not be made so that their interior space is cylindrical.

　　(B) Refrigerators would not be made to have a window in front for easy viewing of their contents without opening the door.

　　(C) The problem of spoilage of refrigerated food is not amenable to any solution based on design changes.

　　(D) Refrigerators are so well designed that there are bound to be drawbacks to any design change.(A)

　　(E) Rotating shelves would be designed to rotate only while the refrigerator door was open.

　　3. It would cost Rosetown one million dollars to repair all of its roads. In the year after completion of those repairs, however, Rosetown would thereby avoid incurring three million dollars worth of damages, since currently Rosetown pays that amount annually in compensation for damage done to cars each year by its unrepaired roads.

　　Which of the following, if true, gives the strongest support to the argument above?

　　(A) Communities bordering on Rosetown also pay compensation for damage done to cars by their unrepaired roads.

　　(B) After any Rosetown road has been repaired, several years will elapse before that road begins to damage cars.

　　(C) Rosetown would need to raise additional taxes if it were to spend one million dollars in one year on road repairs.

　　(D) The degree of damage caused to Rosetown’s roads by harsh weather can vary widely from year to year.(B)

　　(E) Trucks cause much of the wear on Rosetown’s roads, but owners of cars file almost all of the claims for compensation for damage caused by unrepaired roads.

　　4. Two experimental garden plots were each planted with the same number of tomato plants. Magnesium salts were added to the first plot but not to the second. The first plot produced 20 pounds of tomatoes and the second plot produced 10 pounds. Since nothing else but water was added to either plot, the higher yields in the first plot must have been due to the magnesium salts.

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

　　(A) A small amount of the magnesium salts from the first plot leached into the second plot.

　　(B) Tomato plants in a third experimental plot, to which a high-nitrogen fertilizer was added, but no magnesium salts, produced 15 pounds of tomatoes.

　　(C) Four different types of tomatoes were grown in equal proportions in each of the plots.

　　(D) Some weeds that compete with tomatoes cannot tolerate high amounts of magnesium salts in the soil.(E)

　　(E) The two experimental plots differed from each other with respect to soil texture and exposure to sunlight.

　　5. Archaeologists have found wheeled ceramic toys made by the Toltec, twelfth-century inhabitants of what is now Veracruz. Although there is no archaeological evidence that the Toltec used wheels for anything but toys, some anthropologists hypothesize that wheeled utility vehicles were used to carry materials needed for the monumental structures the Toltec produced.

　　Which of the following, if true, would most help the anthropologists explain the lack of evidence noted above?

　　(A) The Toltec sometimes incorporated into their toys representations of utensils or other devices that served some practical purpose.

　　(B) Any wheeled utility vehicles used by the Toltec could have been made entirely of wood, and unlike ceramic, wood decays rapidly in the humid climate of Veracruz.

　　(C) Carvings in monument walls suggest that the Toltec’s wheeled ceramic toys sometimes had ritual uses in addition to being used by both children and adults as decorations and playthings.

　　(D) Wheeled utility vehicles were used during the twelfth century in many areas of the world, but during this time wheeled toys were not very common in areas outside Veracruz.(B)

　　(E) Some of the wheeled ceramic toys were found near the remains of monumental structures.

　　6. Demographers doing research for an international economics newsletter claim that the average per capita income in the country of Kuptala is substantially lower than that in the country of Bahlton. They also claim, however, that whereas poverty is relatively rare in Kuptala, over half the population of Bahlton lives in extreme poverty. At least one of the demographers’ claims must, therefore, be wrong.

　　The argument above is most vulnerable to which of the following criticisms?

　　(A) It rejects an empirical claim about the average per capita incomes in the two countries without making any attempt to discredit that claim by offering additional economic evidence.

　　(B) It treats the vague term “poverty” as though it had a precise and universally accepted meaning.

　　(C) It overlooks the possibility that the number of people in the two countries who live in poverty could be the same even though the percentages of the two populations that live in poverty differ markedly.

　　(D) It fails to show that wealth and poverty have the same social significance in Kuptala as in Bahlton.(E)

　　(E) It does not consider the possibility that incomes in Kuptala, unlike those in Bahlton, might all be very close to the country’s average per capita income.

　　7. Normally, increases in the price of a product decrease its sales except when the price increase accompanies an improvement in the product. Wine is unusual, however. Often increases in the price of a particular producer’s wine will result in increased sales, even when the wine itself is unchanged.

　　Which of the following, if true, does most to explain the anomaly described above?

　　(A) The retail wine market is characterized by an extremely wide range of competing products.

　　(B) Many consumers make decisions about which wines to purchase on the basis of reviews of wine published in books and periodicals.

　　(C) Consumers selecting wine in a store often use the price charged as their main guide to the wine’s quality.

　　(D) Wine retailers and producers can generally increase the sales of a particular wine temporarily by introducing a price discount.(C)

　　(E) Consumers who purchase wine regularly generally have strong opinions about which wines they prefer.

　　8. The recent decline in land prices has hurt many institutions that had invested heavily in real estate. Last year, before the decline began, a local college added 2,000 acres to its holdings. The college, however, did not purchase the land but received it as a gift. Therefore the price decline will probably not affect the college.

　　Which of the following, if true, casts most doubt on the conclusion above?

　　(A) The 2,000 acres that the college was given last year are located within the same community as the college itself.

　　(B) The college usually receives more contributions of money than of real estate.

　　(C) Land prices in the region in which the college is located are currently higher than the national average.

　　(D) Last year, the amount that the college allocated to pay for renovations included money it expected to receive by selling some of its land this year.(D)

　　(E) Last year, the college paid no property taxes on land occupied by college buildings but instead paid fees to compensate the local government for services provided.