报考美国研究生的考生需要进行
准备托福对GRE也是有益的，托福和GRE中不少话题类型和题目类型是重复的，比如冰川，火星，maya水文明等话题都是类似的。尤其是火星，托福中有三篇考察火星的文章，分别是关于TPO8(火星上的流水)，TPO16(太阳系中的行星)，TPO25(火星表面)其中，火星地表特征这一篇在GRE中也有考察。
对比一下会发现，文章是有颇多信息是相关并且类似的。比如都在探讨火星的地表特征，洼陷的地貌;造成这种地貌的原因是什么。具体来说，托福讨论火星地表的多个地表特征(地表上类似火山的特征以及地表上各种坑)，并且针对坑的形成有比较具体的内容描述。GRE只针对一个特征(火星北部的低洼地表)进行陈述，重点落在探讨形成这个地表特征的原因。
两者的差异可以从两个角度来看，一方面是文章的行文重点。托福因为文章通常在600-700字之间，有大量的细节和论证过程。文章很多在说明火星表面的坑的形成原因(和干燥气候有关)，坑能够提供的信息(星球的年纪和地表情况)，没有很明显的观点对比或者态度变化。简言之，好似一篇说明文。而GRE文章说明性内容很少(仅仅第一段介绍火星北部地表情况)第二段开始就是不同的观点来解释火星北部的低洼地表，其中有逻辑关系词However表明观点的变化，以及指示作者态度的呈现。观点变化和作者态度，就是GRE的重点和考点。
另一方面，是选项的设置。因为托福的文章中细节比较多，所以细节题的考察也是比较多的，比如下面这个考题：
The detailed appearance of Martian impact craters provides an important piece of information about conditions just below the planet’s surface. Martian craters are surrounded by ejecta (debris formed as a result of an impact) that looks quite different from its lunar counterparts. A comparison of the Copernicus crater on the Moon with the (fairly typical) crater Yuty on Mars demonstrates the differences. The ejecta surrounding the lunar crater is just what one would expect from an explosion ejecting a large volume of dust, soil, and boulders. ■However, the ejecta on Mars gives the distinct impression of a liquid that has splashed or flowed out of crater. ■Geologists think that this fluidized ejecta crater indicates that a layer of permafrost, or water ice, lies just a few meters under the surface.■Explosive impacts heated and liquefied the ice, resulting in the fluid appearance of the ejecta.
12. According to paragraph 6, the ejecta of Mars’s crater Yuty differs from the ejecta of the Moon’s Copernicus crater in that the ejecta of the Yuty crater
○ Has now become part of a permafrost layer
○ Contains a large volume of dust, soil and boulders
○ Suggests that liquid once came out of the surface at the crater site
○ Was thrown a comparatively long distance from the center of the crater
针对段落中的火星的坑Yuty的喷出物和月亮的坑的喷出物的区别进行考察，根据题干中具体的对比对象描述可以定位原文句子，大概是
“A comparison of the Copernicus crater on the Moon with the (fairly typical) crater Yuty on Mars demonstrates the differences. The ejecta surrounding the lunar crater is just what one would expect from an explosion ejecting a large volume of dust, soil, and boulders. However, the ejecta on Mars gives the distinct impression of a liquid that has splashed or flowed out of crater.”
再根据题干的问题点是落脚在the ejecta of Yuty crater，也就是火星上的喷出物，所以具体是“However, the ejecta on Mars gives the distinct impression of a liquid that has splashed or flowed out of crater.”这句话，即然而，火星的喷出物明确表明是从坑里流出或者溅出的液体。 最接近的选项就是C Suggests that liquid once came out of the surface at the crater site表明从坑表面出来的液体。正确!
GRE的文章中也有类似的考题
What accounts for the low-lying, ……
Is Mars’s north similarly characterized by a sort of crust different from other areas of the planet?Some researchers do see signs of tectonic activity surrounding the northern basin that suggest thatit was created through the formation of new crust, like ocean basins on Earth. However, McGillpoints to Northern bedrock structures that predate the features said to mark the start of the tectonicprocess. McGill instead believes that through some novel mechanism the ancient surface sank toits current depth as a single unit. This would explain why features around the basin’s edge, whichwould have formed as the surface dropped, seem to be younger than structures at its floor.The third possibility is that …...
As presented in the passage, McGill’s account of the formation of Mars’s northern basin differsfrom the other mentioned in that it alone
A. explains the formation of certain northern bedrock features
B. does not specify the force that caused the northern basin to be lower than its surroundings
C. takes the northern basin to be a landform that is not analogous to any found on Earth
D. denies that features around the northern basin are the result of tectonic activity
E. attributes the creation of the northern lowlands to processes occurring within the planet
没有具体指代段落了，根据题干中M的名字进而定位文章内容。题干的核心在于M的解释和别的解释的不同之处，那么就是寻找原文M的独到观点，即“McGill instead believes that through some novel mechanism the ancient surface sank toits current depth as a single unit.”。相反，M认为通过一些新颖的机制，以前的表面沉降到现在的深度是单一事件。GRE选项和托福的选项有很大区别，选项不是原文句子的直接转写了。根据文意，再结合选项A错误，并没有解释特定的基层的特点。B正确，文中只提及M认为有新颖的机制，并没有具体说是什么机制，选项符合。C，根据文意，地形上有类似于地球的海洋盆地，这个选项本身也不符合题干。D，否认北部盆地特点是由地壳活动造成的。文中M并没有否认，只是指出了证据上的不可靠性，所以C是错误的。E，将北部低地是由行星内的过程形成，文中M并没有这么表明，错误。需要根据文意，加以提炼和总结，得到答案是B。
