2月GMAT阅读机经：lost city.

　　十二月的机经随着新年的钟声已经分享完毕，紧接着2月的GMAT机经就整理出来了，为大家分享关于lost city的机经，希望大家能感受到这股暖意，并把它化为能量，在GMAT考试的道路上勇往直前。

　　这一篇是元叔直接在考场堵到的 就直接从原来的机经里面找出来了~

　　快给尽职尽责的元叔鼓掌~~~~~~

　　本月原始 【By KevinChin】

　　阅读题，这篇挺长有点难。 楼主回忆零零碎碎，慎看

　　讲的是地球出现生命前，有个地方(貌似是深海的某个区域)叫做 ***City，这个地方的水跟地球其他地方的水不一样，会产生一些物质，而这些物质最后形成最初的生命。

　　第一段好像有个general view，然后话锋一转，后面几段全都是说明main idea(这个叫做***City的地方形成的最初的生命)的。后面每段开头都是该段的中心论点，这个挺好看。

　　本月原始 【By dream启程】

　　2. lost city。。。恩恩，有一个highlight题划了句子：就是什么ancient people在那个有神奇的物质的地方生活can choose the stage of biological path云云，问是什么意思，貌似是说明我们的祖先可以在那个环境生活啊之类的那个选项?

　　【V1】 LOST CITY

　　大意是说，科学家在水下发现了一个lost city，什么什么样的， 然后某某就带一队人开始研究(这里有题，说关于lost city的描述哪个最准确)。发现这个水下的lost city含有一些奇特物质探索methane什么的几种物质，然后又起化学反应啊之类的，这些物质可以追溯到多少年前，跟生命起源时候的物质一样 (这里也有题，说这些物质能说明什么问题)~~然后科学家又说这些物质跟外星球的物质差不多，这可能说明多少多少年前，外星球也存在和地球一样的生命。然后又特别说明一种物质M，举了个对比的例子(这里忘了，但是有题，问你作者举这个M起什么作用?答案里有--a,为了证明上一段观点blabla，B. 为了引出下一段blabla)

　　最后一段是说通过研究这个lost city和它的各种成分，提出了jupiter啊，mars啊，还有水星啊什么的都可能早就有生命之类的。。。。。。(还有题，说这个文章作者是什么structure~我选的是：propose a scientific report and some evidence 大概这个意思)

　　题目：1、关于lost city的描述，哪个最准确

　　2、这些物质能说明什么问题?

　　3、这个文章的结构是什么?

　　疑似原文

　　原文出处：

　　www.aoji.cn

　　感谢AIVAR考后回忆

　　有用的段落：

　　One such revelation occurred in December 2000.An expedition mapping a submerged mountain known as the Atlantis Massif, midwaybetween Bermuda and the Canary Islands and half a mile under the surface of theNorth Atlantic, came across a pillar of white rock as tall as a 20-storybuilding rising from the sea?floor. Using the remotely operated ArgoII vehicleand the manned submersible Alvin, scientists surveyed and sampled themysterious formation. Although time constraints limited their investigation toa single Alvin dive, the researchers were able to collect enough information todetermine that the white pillar was just one of several such structures in thearea that were emitting heated seawater. They had discovered a field of undersea hot springs theynamed the Lost City Hydrothermal Field. It was unlike anything seen bore, includingthe now famous black smokers.

　　Strange Chemistry

　　Scientists have known about underseahydrothermal ventssince the 1970s. The black smoker systems are the most familiar; they occur atmid-ocean ridges—those strings of volcanoes overlying spots where tectonicplates are pulling away from one another. The water at these vents can reachtemperatures above 400 degrees Celsius because of their proximity to moltenrock. With a pH similar to lemon juice, the scorching water leaches sulfide,iron, copper and zinc as it filters through the volcanic rocks below theseafloor. As this hot,acidic fluid then rises back to the surface of the seafloor, it is discharged through the ventsintocold seawater,where the dissolved metal sulfides quickly cool and precipitate out of thluid, producing a cloudy mix that looks like billowing black smoke. These metal sulfidesaccumulate into ever taller chimneys atop the vents. Despite their hostilechemistry, the areas surrounding these vents teem with exotic animals, such as giant, red-tippedRiftia tube worms, which lack both mouths and guts but thrive by a symbioticassociation with internal bacteria that consume poisonous hydrogen sulfide gasemanating from the vents.

　　Compared with the savage black smokerenvironment, the Lost City vents are eerily tranquil.安静 Locatedabout 15 kilometers to the west of the tectonic plate boundary at theMid-Atlantic Ridge, this vent field atop the Atlantis Massif is too distant forrising magma to heat the fluids to the blistering temperatures found at blacksmokers. Instead the water is heated by circulation through the merely warmrock below, and the highest measured temperature is only 90 degrees C. Neither arethe Lost City fluids acidic. They are alkaline, with a pH between 9 and 11—similar to milk ofmagnesia or household ammonia solution. Because these waters cannot readilydissolve high concentrations of metals such as iron and zinc, Lost City does not produce themetal sulfideplumes that characterize black smokers. Rather Lost City vent waters are richin calcium, which on mixing with seawater produces calcium carbonate (limestone). Thislimestone forms giant whitechimneys, the largest of which towers nearly 60 meters above thesea?floor—significantlytaller than the loftiest black smoker chimney.

　　Hydrogen is full of energy as a consequence of its ability to transfer electrons to othercompounds, such as oxygen, releasing energy in the process. Compoundsthat can readily donate electrons to other compounds are described somewhatconfusingly as “chemically reduced.” Scientists have long suspected that reduced gases played animportant role in the origin of life on Earth. In the 1920s Russian biochemistAlexander Oparin and British evolutionary biologist J.B.S. Haldane eachsuggested that the primitive atmosphere of Earth might have been very rich inreduced gases such as methane, ammonia and hydrogen. If the atmosphere had highconcentrations of these gases, they proposed, the chemical ingredients required for life might havormed spontaneously.

　　Lost City is a natural laboratory for testingthese ideas. In 2008 chemist Giora Proskurow?ski of the Woods HoleOceanographic Institution and his colleagues published a paper in the journalScience demonstrating that the hydrothermal fluids at Lost City do indeedcontain small organic compounds such as methane, ethane and propane. Other worksuggests that the reactions at Lost City also produce small organic acids suchas formate and acetate. Together these findings confirm that the reducedconditions at the Lost City vents could support the types of chemical reactionsnecessary to create organic compounds from inorganic compounds—a simple butcritical step in prebiotic chemistry.

　　The findings from Lost City also bolsterhypotheses about where else in our solar system life might exist or haveexisted in the past. Any planet or moon containing both peridotite and liquid water—theingredients necessary for serpentinization—could conceivablysupport life-forms analogous to microbes at Lost City. Evidence ofthese components is strongest on Mars and on Jupiter’s moon Europa. Indeed,researchers have already detected methane in the modern Martian atmosphere.Whether it comes from microbes or chemical reactions in the planet’s rocks—orboth—remains uncertain, however

　　以上就是关于GMAT机经的全部内容，考生朋友可以有选择的看看，最后需要提醒各位的是，GMAT机经虽然会对我们解题有所帮助，但是在考场中即使题目很像也要避免秒选，最后祝大家都能考出好成绩。