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2010年12月英语四级考试模拟试题及答案PartIWriting(30minutes)Directions:Forthispart,youareallowed30minutestowriteacompositiononetopic:CityProblems.Youshouldwriteatleast120wordsfollowingtheoutlinegivenbelowinChinese:1.越来越多的人涌入大城市，有些问题随之产生2.比较明显的大问题有……3.我对这种现象的想法CityProblemsPartIIReadingComprehension(SkimmingandScanning)(15minutes)Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,markY(forYES)ifthestatementagreeswiththeinformationgiveninthepassage;N(forNO)ifthestatementcontradictstheinformationgiveninthepassage;NG(forNOTGIVEN)iftheinformationisnotgiveninthepassage.Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.ScientistsWeighOptionsforRebuildingNewOrleansAsexpertsponderhowbesttorebuildthedevastated(毁坏)city,onequestioniswhethertowalloff—orworkwith—thewater.EvenbeforethedeathtollfromHurricaneKatrinaistallied,scientistsarecautiouslybeginningtodiscussthefutureofNewOrleans.FewseemtodoubtthatthisvitalheartofU.S.commerceandculturewillberestored,butexactlyhowtorebuildthecityanditsdefensestoavoidarepeatcatastropheisanopenquestion.PlansforimprovingitsleveesandrestoringthebarrierofwetlandsaroundNewOrleanshavebeenonthetablesince1998,butfederaldollarsneededtoimplementthemneverarrived.Afterthetragedy,that'sboundtochange,saysJohnDay,anecologistatLouisianaStateUniversity(LSU)inBatonRouge.Andifthereisanupsidetothedisaster,hesays,it'sthat'nowwe'vegotacleanslatetostartfrom.ManyarelookingforguidancetotheNetherlands,acountrythat,justlikebowl-shapedNewOrleans,sitsmostlybelowsealevel,keepingthewateratbaywithaconstructionofamazingscaleandcomplexity.Others,pointingtoVenice'slong-standingadaptations,sayit'sbesttoletwaterflowthroughthecity,depositingsedimenttooffsetgeologicsubsidence—amodelthatwouldrequirearadicalrethinkingofarchitecture.Anotherideaistoletnaturehelpbyrestoringthewetlandbuffersbetweenseaandcity.Butbeforetheoptionscanbeweighed,severalunknownswillhavetobeaddressed.Oneispreciselyhowthecurrentdefensesfailed.Toanswerthat,LSUcoastalscientistsPaulKempandHassanMashriquiarepickingtheirwaythroughthedestroyedcityandsurroundingregion,reconstructingthesizeofwatersurgesbymeasuringtelltalemarksleftonthesidesofbuildingsandhighwaystructures.TheyarefeedingthesedataintoasimulationofthewindandwateraroundNewOrleansduringitsordeal.Wecan'tsayforsureuntilthisjobisdone,saysDay,buttheemergingpictureisexactlywhatwe'vepredictedforyears.Namely,severalcanals—includingtheMRGO,whichwasbuilttospeedshippinginthe1960s—havethecombinedeffectoffunnelingsurgesfromtheGulfofMexicorighttothecity'seasternleveesandthelakesystemtothenorth.Thosesurgesaretoblamefortheflooding.Oneofthefirstthingswe'llseedoneisthecompletebackfillingoftheMRGOcanal,predictsDay,whichcouldtakeacoupleofyears.Thelevees,whichhavebeenprovisionallyrepaired,willbeshoredupfurtherinthemonthstocome,althoughtheirlong-termfateisunclear.Betterleveeswouldprobablyhavepreventedmostofthefloodinginthecitycenter.Toprovidefurtherprotection,amobiledamsystem,muchlikeastormsurgebarrierintheNetherlands,couldbeusedtocloseoffthemouthofLakePontchartrain.Butmostexpertsagreethattheseareshort-termfixes.ThebasicproblemforNewOrleansandtheLouisianacoastlineisthattheentireMississippiRiverdeltaissubsidinganderoding,plungingthecitydeeperbelowsealevelandremovingathickcushionofwetlandsthatoncebufferedthecoastlinefromwindandwaves.Partofthesubsidenceisgeologicandunavoidable,butthereststemsfromtheleveesthathavehemmedintheMississippiallthewaytoitsmouthfornearlyacenturytopreventfloodsandfacilitateshipping.Asaresult,riversedimentisnolongerspreadacrossthedeltabutdumpedintotheGulfofMexico.Withoutaconstantstreamoffreshsediment,thebarrierislandsandmarshesaredisappearingrapidly,withaquarter,roughlythesizeofRhodeIsland,alreadygone.Afteryearsofpoliticalwrangling,abroadgrouppulledtogetherbytheLouisianagovernmentin1998proposedamassive$14billionplantosavetheLouisianacoasts,calledCoast2050(nowmodifiedintoaplancalledtheLouisianaCoastalAreaproject).Wetlandrestorationwasakeycomponent.It'soneofthebestandcheapesthurricanedefenses,saysDay,whochaireditsscientificadvisorycommittee.Althoughtheplanwasnevergivenmorethantokenfunding,ateamledbyDayhasbeenconductingapilotstudysince2000,divertingpartoftheMississippiintothewetlandsdownstreamofthecity.Theresultsareasgoodaswecouldhavehoped,hesays,withlandlevelsrisingatabout1centimeterperyear—enoughtooffsetrisingsealevels,saysDay.Evenifthewetlandswererestoredandnewleveeswerebuilt,thecombinationofgeologicsubsidenceandrisingsealevelswilllikelysinkNewOrleansanothermeterby2100.Theproblemmightbesolvedbyanotherambitiousplan,saysRoelBoumans,acoastalscientistattheUniversityofVermontinBurlingtonwhodidhisph.D.atLSU:shoringupthelowestlandwithaslurryofsedimentpipedinfromtheriver.Themajorityofthebuildingsinthefloodedareaswillhavetoberazedanyway,hesays,sowhynottakethisopportunitytofixtherootoftheproblem?TherivercoulddepositenoughsedimenttoraisethebottomoftheNewOrleansbowltosealevelin50to60years,heestimates.Inthemeantime,peoplecouldliveintheseareasV