37. If the airspace around centrally located airports were restricted to commercial airliners and only those private planes equipped with radar, most of the private-plane traffic would be forced to sue outlying airfields. Such a reduction in the amount of private-plane traffic would reduce the risk of midair collision around the centrally located airports. Which of the following, if true, would most strengthen the conclusion drawn in the second sentence? A. Commercial airliners are already required by law to be equipped with extremely sophisticated radar systems. B. Centrally located airports are experiencing overcrowded airspace primarily because f sharp increases in commercial-airline traffic. C. Many pilots of private planes would rather buy radar equipment than be excluded from centrally located airports. D. The number of midair collisions that occur near centrally located airports has decreased in recent years. E. Private planes not equipped with radar systems cause a disproportionately large number of midair collisions around centrally located airports.
38. Which of the following best completes the passage below? Established companies concentrate on defending what they already have. Consequently, they tend not to be innovative themselves and tend to underestimate the effects of the innovations of others. The clearest example of this defensive strategy is the fact that___. A. ballpoint pens and soft-tip markers have eliminated the traditional market for fountain pens, clearing the way for the marketing of fountain pens as luxury or prestige items B. a highly successful automobile was introduced by the same company that had earlier introduced a model that had been a dismal failure C. a once-successful manufacturer of slide rules reacted to the introduction of electronic calculators by trying to make better slide rules D. one of the first models of modern accounting machines, designed for use in the banking industry, was purchased by a public library as well as by banks E. the inventor of a commonly used anesthetic did not intend the product to be used by dentists, who currently account for almost the entire market for that drug.
39. Most archaeologists have held that people first reached the Americas less than 20,000 years ago by crossing a land bridge into North America. But recent discoveries of human shelters in South America dating from 32,000 years ago have led researchers to speculate that people arrived in South America first, after voyaging across the Pacific, and then spread northward. Which of the following, if it were discovered, would be pertinent evidence against the speculation above? A. A rock shelter near Pittsburgh, Pennsylvania, contains evidence of use by human beings 19,000 years ago. B. Some North American sites of human habitation predate any sites found in South America. C. The climate is warmer at the 32,000-year-old South American site than at the oldest known North American site. D. The site in South America that was occupied 32,000 years ago was continuously occupied until 6,000 years ago. E. The last Ice Age, between 11,500 and 20,000 years ago, considerably lowered worldwide sea levels.
40. In Asia, where palm trees are non-native, the trees’ flowers have traditionally been pollinated by hand, which has kept palm fruit productivity unnaturally low. When weevils known to be efficient pollinators of palm flowers were introduced into Asia in 1980, palm fruit productivity increased-by up to fifty percent in some areas-but then decreased sharply in 1984. Which of the following statements, if true, would best explain the 1984 decrease in productivity? A. Prices for palm fruit fell between 1980 and 1984 following the rise in production and a concurrent fall in demand. B. Imported trees are often more productive than native trees because the imported ones have left behind their pests and diseases in their native lands. C. Rapid increases in productivity tend to deplete trees of nutrients needed for the development of the fruit-producing female flowers. D. The weevil population in Asia remained at approximately the same level between 1980 and 1984. E. Prior to 1980 another species of insect pollinated the Asian palm trees, but not as efficiently as the species of weevil that was introduced in 1980.
AA： The following appeared in the editorial section of a campus newspaper.“Because occupancy rates for campus housing fell during the last academic year, so did housing revenues. To solve the problem, campus housing officials should reduce the number of available housing units, thereby increasing the occupancy rates. Also, to keep students from choosing to live off-campus, housing officials should lower the rents, thereby increasing demand.”作者: daisyの小夢想 时间: 2011-10-26 08:02
37. The second sentence concludes that the reduction described in the first sentence would reduce the risk of midair collisions around centrally located airports. According to E, such a reduction would remove precisely the kind of plane that causes a disproportionate number of midair collisions. Thus, E is the best answer. Because A does not address the question of whether reducing private-plane traffic would reduce the risk of midair collisions, it is inappropriate. B and C concern the question of whether or not the proposed restrictions would reduce plane traffic, but not the question of whether any resulting reductions would reduce the risk of midair collisions. That the number of midair collisions has recently decreased is irrelevant to whether the proposed reduction would further reduce collisions, so D is inappropriate.
38. C is a clear example of a defensive, non-innovative strategy that underestimates the effects of others’ innovations: the slide-rule manufacturer acted as though any advantages offered by the newer and fundamentally different technology of a competing product, the electronic calculator, could be matched by improving the older, more familiar product. C is thus the best answer. A is not an example of the defensive strategy; it presents a case in which innovative products displaces an older product from its traditional market but in so doing made possible a new marketing strategy for the older product. B is not clearly an example of the defensive strategy since it does no describe a response to the innovations of others. D and E are cases of new products finding unintended users, not of responses to innovations of others, so they are not examples of the defensive strategy described.
39. The reasoning behind the researchers’ speculation that people first arrived in South America is that there is no evidence of North American sites that predate the human shelters discovered in South America. If it were discovered that, as B states, some North American sites predate those in South America, the reasoning behind the speculation would no longer hold. Thus, B is the best answer. The facts related in A and E both involve time periods occurring after those discussed in the passage, and so create no conflict with the speculation. Although C and D describe discoveries about the South American site, neither the relative climates nor the duration of occupation mentioned provides evidence against the speculation.
40. If C is true, the rapid increase in productivity among Asian palm trees after 1980 probably depleted nutrients needed for the development of fruit-producing flowers. Thus, C explains why the palms’ productivity could subsequently decline, and is the best answer. A relates a drop in the price of palm fruit to a rise in production and a fall in demand, but it does not explain the subsequent drop in the trees’ productivity. B gives no reason for the decrease in productivity of the trees introduced to Asia. D does not explain the decrease in productivity, since the stability of the weevil population described would support stability of palm fruit productivity between 1980 and 1984 rather than a decrease. Because E describes the pollination of the trees prior to 1980, it cannot explain a change occurring in 1984.作者: daisyの小夢想 时间: 2011-10-26 08:03
AA 1， 入住率低可能是因为学生人数减少等原因造成的 2， 同时减少供给和降低房费可能会抵消入住率提高而带来的收入提高效应而有余 3， 就算不会完全抵消仍然有其他原因影响收入例如说学生进入后的维修等等。 boosting rental maintenance oppressive seriousness trivailize
1， 忽略他因：单纯地说问题所在是rent. 但实际上可能有很多其他的因素：房子的condition, security, cleaning service，noisy surroundings等等。 2， 过去不能推广到未来：很可能变化了——比如enrollments of students have sharply increased。所以，很可能减少available的数量可能不是合适的做法。 3， 减少提供的房子，降低房租，很可能导致收入下降。作者: UlysessHope 时间: 2011-10-26 12:52
占座 晚上补作业作者: bonfin 时间: 2011-10-26 16:48
E C B C作者: 小抽 时间: 2011-10-26 20:13
E C B C