GRE阅读真题汇总 今天给大家整理了GRE阅读真题之PP2-1 Passage 1,一起来学习吧，下面就和大家分享，来欣赏一下吧。GRE阅读真题之PP2-1 Passage 1PP2-1Passage 1Even after numerous products made with artificial sweeteners became available, sugar consumption per capita continue to rise. Now manufactures are introducing fat-free versions of various foods that they claim have the taste and texture of the traditional high-fat versions. Even if the manufacturers claim is true, given that the availability of sugar-free foods did not reduce sugar consumption, it is unlikely that the availability of these fat-free foods will reduce fat consumption.1. Which of the following, if true, most seriously undermines the argument?A. Several kinds of fat substitute are available to manufacturers, each of which gives a noticeably different taste and texture to products that contain it.B. The products made with artificial sweeteners did not taste like products made with sugar.C. The foods brought out in sugar-free versions did not generally have reduced levels of fat, but many of the fat-free versions about to be introduced are low in sugar.D. People who regularly consume products containing artificial sweeteners are more likely than others to consume fat-free foods.E. Not all foods containing fat can be produced in fat-free versions.GRE阅读真题之PP2-1 Passage 2PP2-1Passage 2Recent studies of sediment in the North Atlantics deep waters reveal possible cyclical patterns in the history of Earths climate. The rock fragments in these sediments are too large to have been transported there by ocean currents; they must have reached their present locations by traveling in large icebergs that floated long distances from their point of origin before melting. Geologist Gerard Bond noticed that some of the sediment grains were stained with iron oxide, evidence that they originated in locales where glaciers had overrun outcrops of red sandstone. Bonds detailed analysis of deep-water sediment cores showed changes in the mix of sediment sources over time: the proportion of these red-stained grains fluctuated back and forth from lows of 5 percent to highs of about 17 percent, and these fluctuation occurred in a nearly regular 1,500-year cycle.Bond hypothesized that the alternating cycles might be evidence of changes in ocean-water circulation and therefore in Earths climate. He knew that the sources of the red-stained grains were generally close to the North Pole than were the places yielding a high proportion of “clean” grains. At certain times, apparently, more icebergs from the Arctic Ocean in the far north were traveling south well into the North Atlantic before melting and shedding their sediment.Ocean waters are constantly moving, and water temperature is both a cause and an effect of this movement. As water cools, it becomes denser and sinks to the oceans bottom. During some periods, the bottom layer of the worlds oceans comes from cold, dense water sinking in the far North Atlantic. This causes the warm surface waters of the Gulf Stream to be pulled northward. Bond realized that during such periods, the influx of these warm surface waters into northern regions could cause a large proportion of the icebergs that bear red grains to melt before traveling very far into the North Atlantic. But sometimes the oceans dynamic changes, and waters from the Gulf Stream do not travel northward in this way. During these periods, surface waters in the North Atlantic would generally be colder, permitting icebergs bearing red-stained grains to travel farther south in the North Atlantic before melting and depositing their sediment.The onset of the so-called Little Ice Age (1300-1860), which followed the Medieval Warm Period of the eighth through tenth centuries, may represent the most recent time that the oceans dynamic changed in this way. If ongoing climate-history studies support Bonds hypothesis of 1,500-year cycles, scientists may establish a major natural rhythm in Earths temperatures that could then be extrapolated into the future. Because the midpoint of the Medieval Warm Period was about A.D. 850, an extension of Bonds cycles would place the midpoint of the next warm interval in the twenty-fourth century.1. According to the passage, which of the following is true of the rock fragments contained in the sediments studied by Bond?A. The majority of them are composed of red sandstone.B. They must have reached their present location over 1,500 years ago.C. They were carried by icebergs to their present location.D. Most of them were carried to their present location during a warm period in Earths climatic history.E. They are unlikely to have been carried to their present location during the Little Ice Age.2. In the final paragraph of the passage, the author is concerned primarily withA. Answering a question about Earths climatic historyB. Pointing out a potential flaw in Bonds hypothesis