大学英语四级试题模拟试卷五

新东方英语四级：四级qq群：238407043新东方英语四级：四级qq群：238407043PartIWriting(30minutes)Directions:Forthispart,youareallowed30minutestowriteacompositiononthetopicChoosinganOccupation.Youshouldwriteatleast120wordsfollowingtheoutlinegivenbelowinChinese:1.选择职业是一个人要面对的众多难题之一。2.需要花时间去选择职业。3.选择职业时可以向多人寻求建议和帮助。ChoosinganOccupation-----------------------------------------------------------------------------------------------------------------------------------PartIIReadingComprehension(SkimmingandScanning)(15minutes)Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,choosethebestanswerfromthefourchoicesmarked[A],[B],[C]and[D].Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.WillWeRunOutofWater?Pictureaghostshipsinkingintothesand,lefttorotondrylandbyarecedingsea.Thenimagineduststormssweepinguptoxicpesticidesandchemicalfertilizersfromthedryseabedandspewingthemacrosstownsandvillages.Seemlikeascenefromamovieabouttheendoftheworld?ForpeoplelivingneartheAralSeainCentralAsia,it'salltooreal.Thirtyyearsago,governmentplannersdivertedtheriversthatflowintotheseainordertoirrigate(providewaterfor)farmland.Asaresult,theseahasshrunktohalfitsoriginalsize,strandingshipsondryland.Theseawaterhastripledinsaltcontentandbecomepolluted,killingall24nativespeciesoffish.Similarlarge-scaleeffortstoredirectwaterinotherpartsoftheworldhavealsoendedinecologicalcrisis,accordingtonumerousenvironmentalgroups.Butmanycountriescontinuetobuildmassivedamsandirrigationsystems,eventhoughsuchprojectscancreatemoreproblemsthantheyfix.Why?Peopleinmanypartsoftheworldaredesperateforwater,andmorepeoplewillneedmorewaterinthenextcentury.Growingpopulationswillworsenproblemswithwater,saysPeterH.Gleick,anenvironmentalscientistatthePacificInstituteforstudiesinDevelopment,Environment,andSecurity,aresearchorganizationinCalifornia.Hefearsthatbytheyear2025,asmanyasone-thirdoftheworld'sprojected8.3billionpeoplewillsufferfromwatershortages.WhereWaterGoesOnly2.5percentofallwateronEarthisfreshwater,watersuitablefordrinkingandgrowingfood,saysSandraPostel,directoroftheGlobalWaterPolicyProjectinAmherst,Mass.Twothirdsofthisfreshwaterislockedinglaciersandicecaps.Infact,onlyatinypercentageoffreshwaterispartofthewatercycle,inwhichwaterevaporatesandrisesintotheatmosphere,thencondensesandfallsbacktoEarthasprecipitation(rainorsnow).Someprecipitationrunsofflandtolakesandoceans,andsomebecomesgroundwater,waterthatseepsintotheearth.MuchofthisrenewablefreshwaterendsupinremoteplacesliketheAmazonriverbasininBrazil,wherefewpeoplelive.Infact,theworld'spopulationhasaccesstoonly12,500cubickilometersoffreshwater-abouttheamountofwaterinLakeSuperior.Andpeopleusehalfofthisamountalready.Ifwaterdemandcontinuestoclimbrapidly,saysPostel,therewillbesevereshortagesanddamagetotheaquaticenvironment.新东方英语四级：四级qq群：238407043新东方英语四级：四级qq群：238407043ClosetoHomeWaterwoesmayseemremotetopeoplelivinginrichcountriesliketheUnitedStates.ButAmericanscouldfaceseriouswatershortages,tooespeciallyinareasthatrelyongroundwater.Groundwateraccumulatesinaquifers,layersofsandandgravelthatliebetweensoilandbedrock.(Foreveryliterofsurfacewater,morethan90litersarehiddenunderground.)AlthoughtheUnitedStateshaslargeaquifers,farmers,ranchers,andcitiesaretappingmanyofthemforwaterfasterthannaturecanreplenishit.InnorthwestTexas,forexample,overpumpinghasshrunkgroundwatersuppliesby25percent,accordingtoPostel.Americansmayfaceevenmoreurgentproblemsfrompollution.DrinkingwaterintheUnitedStatesisgenerallysafeandmeetshighstandards.Nevertheless,oneinfiveAmericanseverydayunknowinglydrinkstapwatercontaminatedwithbacteriaandchemicalwastes,accordingtotheEnvironmentalProtectionAgency.InMilwaukee,400,000peoplefellillin1993afterdrinkingtapwatertaintedwithcryptosporidium,amicrobethatcausesfever,diarrheaandvomiting.TheSourceWheredocontaminantscomefrom?Indevelopingcountries,peopledumprawsewageintothesamestreamsandriversfromwhichtheydrawwaterfordrinkingandcooking;about250millionpeopleayeargetsickfromwaterbornediseases.Indevelopedcountries,manufacturersuse100,000chemicalcompoundstomakeawiderangeofproducts.Toxicchemicalspollutewaterwhenreleaseduntreatedintoriversandlakes.(Certaincompounds,suchaspolychlorinatedbiphenyls,orPCBs,havebeenbannedintheUnitedStates.)Butalmosteveryonecontributestowaterpollution.Peopleoftenpourhouseholdcleaners,carantifreeze,andpaintthinnersdownthedrain;allofthesecontainhazardouschemicals.ScientistsstudyingwaterintheSanFranciscoBayreportedin1996that70percentofthepollutantscouldbetracedtohouseholdwaste.Farmershavebeencriticizedforoverusingherbicidesandpesticides,chemicalsthatkillweedsandinsectsbutthatpollutewateraswell.Farmersalsousenitrates,nitrogenrichfertilizerthathelpplantsgrowbutthatcanwreakhavocontheenvironment.Nitratesaresweptawaybysurfacerunofftolakesandseas.Toomanynitratesoverenrichthesebodiesofwater,encouragingthebuildupofalgae,ormicroscopicpla