GRE写作范文下载(10篇).pdf

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1、目录GRE写作范文1：Cohesion-tensionTheory...................................................................................1GRE写作范文2：Americanblackbears..........................................................................................1GRE写作范文3：Coal-firedpowerplants......

2、.................................................................................2GRE写作范文4：Statistics............................................................................................................3GRE写作范文5：ObtainingFreshwaterfromicebergs.....................

3、...............................................3GRE写作范文6：ThesourceofEnergy...........................................................................................4GRE写作范文7：Museums.........................................................................................

4、..................5GRE写作范文8：SkyscrapersandEnvironment.............................................................................5GRE写作范文9：ArareFossilRecord.............................................................................................6GRE写作范文10：TheNobelAc

5、ademy..........................................................................................6GRE写作范文1：Cohesion-tensionTheoryAtmosphericpressurecansupportacolumnofwaterupto10metershigh.Butplantscanmovewatermuchhigher;thesequoiatreecanpumpwatertoitsverytopmorethan100met

6、ersabovetheground.Untiltheendofthenineteenthcentury,themovementofwaterintreesandothertallplantswasamystery.Somebotanistshypothesizedthatthelivingcellsofplantsactedaspumps.Butmanyexperimentsdemonstratedthatthestemsofplantsinwhichallthecellsarekilledcanstillmovewatertoappr

7、eciableheights.Otherexplanationsforthemovementofwaterinplantshavebeenbasedonrootpressure,apushonthewaterfromtherootsatthebottomoftheplant.Butrootpressureisnotnearlygreatenoughtopushwatertothetopsoftalltrees.Furthermore,theconifers,whichareamongthetallesttrees,haveunusual

8、lylowrootpressures.Ifwaterisnotpumpedtothetopofatalltree,andifitisnotpushedtothetopofatalltree,thenwema