如何用經濟學人備考GRE閱讀

　　晉升GRE瀏覽才能不克不及急於求成，考生要在備考階段多下工夫，不但要控制技能，更要晉升常識面，選取《經濟學人》作為備考GRE瀏覽材料是異常明智的選取。本日咱們就看看若何用經濟學人備考GRE瀏覽?

　　Pour some water into a partly full bathtub and the level in the tub will rise. Calculating how much it will rise(how引誘的名詞性從句充任名詞) is straightforward, as long as the surface area of what was already there and the amount being added are known. The same should apply to working out how much the sea level will rise as the world’s ice sheets melt in response to rising global temperatures. But in practice it is not that easy. (預判接下來作者會告知我適才評論辯論的原則其實不實用) Though geographers know the surface area of the oceans, measuring how the masses of the world’s ice sheets are changing has proved hard. Aurélien Mordret of the Massachusetts Institute of Technology, however, thinks he has found a way to make it simpler. He proposes to do it using the vibrations created by ocean waves (預判接下來作者將會重點論述該辦法) .

　　At the moment, geographers monitor the mass of ice sheets in two ways. One employs aircraft to fly over such sheets and reflect laser beams from their surfaces, to record their topography. The other uses satellites to track gravitational fluctuations caused by variations in the amount of ice present. Both techniques work, but both have limitations (先容了兩個傳統辦法和它們的範圍性) . Laser overflights create high-resolution images but are expensive, so can be done only a few times a year. Satellites pass overhead more often, but generate fuzzier pictures.

　　Dr Mordret, however, knew from work conducted (此處 "conducted" 用作曩昔分詞，表現被動) by other research groups that(that此處作為noun modifier潤飾work, 但因為that從句太長所今後置) vibrations created by waves crashing onto the shore are transmitted inland through the Earth’s crust, sometimestravelling (comma + ving為臨近的句子供給分外的信息) thousands of kilometres from the coast. These vibrations can be picked up by seismometers of the sort used to monitor earthquakes. He also knew that the speed at which the vibrations propagate varies with the amount of pressure being exerted on the crust by mountains or glaciers sitting above. That gave him his idea (預判接下來作者要論述新辦法的起源/道理).

　　Propagation speeds vary because many types of rock have small voids within their structure. These lower the velocity of passing vibrations. The greater the proportion of a rock’s volume that is void, the more slowly vibrations will travel through it. If a piece of rock is dry, compressing it will shrink the voids and speed the vibrations up. Water, though, is famously incompressible—more so(so作為代詞指代incompressible) than most rock-forming minerals. If the voids are filled with water, they will thus resist compression. So, putting pressure on wet rock increases the relative volume of the voids, which slows down any passing vibrations.

　　Since an icy overburden will both fill the voids with water and compress the rock, Dr Mordret reasoned that changes in the speed of transmission in rocks under ice sheets will reflect the thickness of the overlying sheet (提出假如的詳細內容) . To test this idea, he and a team of colleagues set up an experiment which made use of existing earthquake sensors at seven monitoring stations in western Greenland, an island almost completely covered by ice sheets....

　　如下是構造剖析

　　先容一個丈量的根本原則，但其實不實用於丈量海平面的上升 → 引出新辦法(P1)

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　　先容兩個舊辦法和它們的弊病(P2)

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　　得出新辦法以前的相幹配景信息(P3)

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　　論述新辦法的起源/道理(P4)

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　　根本新辦法的起源/道理提出假如(P5)

　　以上便是本日小編為眾人分享的若何用經濟學人備考GRE瀏覽，願望對加入GRE測驗的考生有所贊助。想要加入GRE培訓、雅思培訓的考生請選取。末了，小編祝眾人出國留學之路順順遂利!更多出色內容盡在留學GRE測驗頻道。