GMAT閱讀機(jī)經(jīng)整理：加拿大好基友.

　　1月31日GMAT機(jī)經(jīng)換庫，現(xiàn)在整理2月份最新的GMAT閱讀機(jī)經(jīng)，目前是以原始稿為主，這篇主要是關(guān)于加拿大好基友的，考生朋友可以有選擇的看看，希望給大家的備考帶來一些幫助。

　　[V1]

　　楓葉國的兩個(gè)好基友科學(xué)家G和N的故事

　　P1. 來自楓葉國的G發(fā)現(xiàn)了一個(gè)很神奇的現(xiàn)象：河水的形成是受當(dāng)?shù)刂参镉绊懙?貌似是，記不太清了)

　　P2. 這時(shí)，好基友N出現(xiàn)了。他們兩個(gè)一起的發(fā)現(xiàn)加強(qiáng)了G的結(jié)論。

　　P3. 但是，有一小撮科學(xué)家發(fā)現(xiàn)了C現(xiàn)象。這個(gè)用G的結(jié)論怎么解釋呢?

　　P4. 因此科學(xué)家們還需要再做進(jìn)一步觀察

　　[V2]

　　河和河床的變化。一屏半。兩個(gè)加拿大的科學(xué)家。說的是雖然我們現(xiàn)在看到的河流是這樣的，但是好多好多年前，才不是這個(gè)樣子滴。第二段說500m年前如何如何，第三段說420m前發(fā)現(xiàn)的一個(gè)什么巖石能繼續(xù)證明他們的觀點(diǎn)是正確的。

　　問題：

　　主旨題我選的是(to provide evidences to support a claim)

　　[V3]

　　plant with root改變河流的形狀，寬度，深度。。。 cambrian時(shí)期之后，發(fā)現(xiàn)了什么植物的化石還有河流的sediment的變化是同時(shí)發(fā)生的。

　　[V4]

　　有科學(xué)家說，植物對河流有影響，然后Oo科學(xué)家支持。按照套路接下來會反對，說有個(gè)階段，sediment 怎么樣的。噢第一段說了個(gè)Cambrian 時(shí)期怎么樣的，那時(shí)候洪水沖擊吧。第二段提了個(gè)P階段這個(gè)階段直接出題了

　　問題：每段關(guān)系是怎么樣的

　　[V5]

　　還有個(gè)閱讀是講河流的形成的，說是河流會不會是受生長在其周圍的植物影響，從而變寬變窄。舉了在沉積物當(dāng)中發(fā)現(xiàn)什么植物的化石之類的東西。第三段講河流的這些變化也可能是受環(huán)境的影響。什么人類居住的原因。

　　[V6]

　　第二篇：加拿大的好基友，就是河床那個(gè)。

　　P1，加拿大的某個(gè)科學(xué)家提出了一個(gè)關(guān)于河床的在N年前如何形成什么什么的觀點(diǎn)。

　　P2，第一句話就是說這個(gè)觀點(diǎn)被另外一個(gè)科學(xué)家substantiate了，好像是這樣單詞，反正就是支持第一段。

　　P3，提出了以前的河流在沒有植物在岸邊還是什么的時(shí)候，一般都是很淺，很寬的。然后有了植物之后怎么怎么樣。。。。

　　P4，最后一段，說著2個(gè)科學(xué)家還有一個(gè)問題需要研究。在某個(gè)地球的某個(gè)時(shí)期，植物曾經(jīng)大范圍滅絕了。然后他們想通過這個(gè)現(xiàn)象，去證明，如果植物滅絕以后，河流是不是有恢復(fù)到以前的那種又淺又寬的狀態(tài)。

　　問題有問這個(gè)文章的結(jié)構(gòu)，然后還有一些細(xì)節(jié)題。

　　[V7]

　　River形成那篇考了第三段作用,記得有fosill神馬的讓bank和什么的界限更清晰了

　　疑似原文:

　　If Not for Plants, Could Rivers Bend?

　　Geologists strengthen the case that early rooted plants engineered the look of modern rivers

　　Catherine Clabby

　　For decades, the Canadian geologist Martin Gibling has been intrigued by the tough-to-prove hypothesis that land plants created the shape of modern rivers hundreds of millions of years ago.

　　Plant roots reinforced the ground, the thinking goes, creating stable banks that funneled what once were wide, shallow water flows into narrower and deeper channels. By extension, that set the stage for lots of significant Earth history events, including the rise of human civilizations in modern river basins so many millennia later.

　　Now Gibling and postdoctoral scientist Neil Davies, both at Dalhousie University, have strengthened this case. When the pair compared a much-improved plant fossil record with evidence of how rivers changed very long ago, the transitions matched up.

　　“As soon as the plants got a foothold on land and rooted vegetation started, that changed the landscape. Basically plants engineered that landscape as they evolved,” says Davies. He and Gibling have published the findings in both Geology and Earth-Science Reviews.

　　Back in the Cambrian period, which ended some 500 million years ago, the geologic record indicates that rivers were very shallow but wide things, almost floods that allowed rainwater to wash from largely barren solid ground to sea. Deposits lt behind were preserved as sheets of coarse grains, some of which suggest these rivers were 1,000 or more times as wide as they were deep.

　　“There is probably nowhere on Earth where rivers form the way they did bore vegetation,” Gibling says.

　　But by the time of the Silurian- Devonian boundary, some 420 million years ago, the picture found in preserved sedimentary rock changes. The blankets of unconsolidated sediment found in earlier river deposits appear less frequently. It happens just as evidence of land vegetation with root systems also expands in the rock record.

　　In addition, more complex and diverse river remains emerge, including more traces of mud, probably due to the enhanced chemical weathering that plants assist; smaller-sized sand grains; and samples of organic remains. Significantly, shapes shift too.

　　Organized deposits become visible in the remains of highly sinuous, single-thread channels. Evidence of lateral accretion—the digging away of material at the outer bends of a river and the simultaneous deposition of material at the inner bends—is more abundant.

　　There is also variation that appears to be related to the local climate during the times that the rivers flowed. “Bore plants evolved, it didn’t matter if a river was in a polar region, a temperate region or an arid region, the rivers looked the same. Later you find differences,” says Davies, who devoted two and a half years to this project.

　　Edward Cotter, a geologist long on the faculty of Bucknell University, was among the people arguing 30 years ago that rivers went through a big transition during the same period that Gibling and Davies emphasize. He observed it in sedimentary rocks in the central Appalachian Mountains dating from 450 to 250 million years ago. But unlike Gibling and Davies, he had limited evidence with which to extrapolate globally from his observations.

　　“They had a much richer database. They have a much healthier understanding of how rivers run. They went around to different parts of the world and looked with their own eyes,” says Cotter, whose research Gibling and Davies cite in their publications.

　　Using funding from the Canadian government, Davies and Gibling reviewed 144 published reports describing river sediment preserved in the rock record, dating from the Cambrian to the Devonian, to build their case. They visited 34 spots themselves in North America and Europe. And they scrutinized experimental results.

　　One laboratory finding that impressed Gibling was achieved at St. Anthony Falls Laboratory at the University of Minnesota. Working in a tank, researchers there described how vegetation—in this case alfalfa sprouts that were allowed to germinate on banks—transformed a channel that flowed between multiple sandbars into one that self-organized into a single- thread channel.

　　“The strength of the roots of alfalfa was enough to completely change the whole pattern. That generated a meandering river with banks that migrate and are erosion resistant,” Gibling says.

　　Dov Corenblit, an associate professor at the University of Paris who describes himself as a biogeomorphologist, says Davies and Gibling have delivered more than just insight into the history of rivers. They have expanded evidence that the biotic and abiotic features of this planet influence one another.

　　Their findings “may be considered significant progress in the comprehension of one of the most critical phases in the coupling between physical and biological processes on Earth,” Corenblit says.

　　The Dalhousie University geologists aren’t done. They want to explore whether any of the periodic mass extinctions experienced on Earth might have affected the shapes of rivers as well. They are scouring the literature for changes preserved from the end of the Permian, when a lot of plant life was wiped out.

　　“We’ll look to see if rivers reverted to the older form,” Davies says.

　　以上就是關(guān)于加拿大好基友的GMAT閱讀機(jī)經(jīng)原始稿的全部內(nèi)容，考生朋友可有選擇的選用，最后祝大家都能考出好成績。