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 50 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?
Wolves generally avoid human settlements. For this reason, domestic sheep, though essentially easy prey for wolves, are not usually attacked by them. In Hylantia prior to 1910, farmers nevertheless lost considerable numbers of sheep to wolves each year. Attributing this to the large number of wolves, in 1910 the government began offering rewards to hunters for killing wolves. From 1910 to 1915, large numbers of wolves were killed. Yet wolf attacks on sheep increased significantly.Which of the following, if true, most helps to explain the increase in wolf attacks on sheep?
Nitrogen dioxide is a pollutant emitted by automobiles. Catalytic converters, devices designed to reduce nitrogen dioxide emissions, have been required in all new cars in Donia since 1993, and as a result, nitrogen dioxide emissions have been significantly reduced throughout most of the country. Yet although the proportion of new cars in Donia's capital city has always been comparatively high, nitrogen dioxide emissions there have showed only an insignificant decline since 1993.Which of the following, if true, most helps to explain the insignificant decline in nitrogen dioxide emissions in Donia's capital city?
【OG20-P570-637题】Suncorp, a new corporation with limited funds, has been clearing large sections of the tropical Amazon forest for cattle ranching. This practice continues even though greater profits can be made from rubber tapping, which does not destroy the forest, than from cattle ranching, which does destroy the forest.Which of the following, if true, most helps to explain why Suncorp has been pursuing the less profitable of the two economic activities mentioned above?
Which of the following most logically completes the argument? The growing popularity of computer-based activities was widely predicted to result in a corresponding decline in television viewing. Recent studies have found that, in the United States, people who own computers watch, on average, significantly less television than people who do not own computers. In itself, however, this finding does very little to show that computer use tends to reduce television viewing time, since __________.
Wolves generally avoid human settlements. For this reason, domestic sheep, though essentially easy prey for wolves, are not usually attacked by them. In Hylantia prior to 1910, farmers nevertheless lost considerable numbers of sheep to wolves each year. Attributing this to the large number of wolves, in 1910 the government began offering rewards to hunters for killing wolves. From 1910 to 1915, large numbers of wolves were killed. Yet wolf attacks on sheep increased significantly. Which of the following, if true, most helps to explain the increase in wolf attacks on sheep?
Which of the following most logically completes the passage below?Heavy rains during Centralia’s corn planting season prevented some farmers there from planting corn. It is now the planting season for soybeans, another of Centralia’s principal crops, and those fields originally intended for corn are dry enough for planting. Nonetheless, even though soybean prices are unusually high at present, the farmers will leave most of these fields empty rather than plant them with soybeans, since_______.
Two years ago, the government of Runagia increased by 20 percent the government-provided pensions paid to Runagians over 65. The aim of the increase was to stimulate the economy in the rural regions of the country, where most pension recipients live. Statistics, however, show that there has been no increase in economic activity in those regions since then, but that there has been noticeably more spending in the urban areas.Which of the following, if true, most helps to explain why the increase resulted in the unintended state of affairs described?
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12G备考资料