07年6月新英语四级模拟试卷与答案

07年6月新英语四级模拟试卷与答案PartⅠWriting（30minutes）Directions:Forthispart,youareallowedthirtyminutestowriteacompositiononthetopic:AidEducationinChina.Youshouldwriteatleast120wordsfollowingtheoutlinegiveninChinesebelow:1.每年，高校许多大学生受到鼓舞去贫困地区支教。2.支教活动的意义。3.我的看法。提示:在实考试卷中，该试题在答题卡1上。Aid——EducationinChinaPartⅡReadingComprehension（SkimmingandScanning）（15minutes）Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,markY（forYES）ifthestatementagreeswiththeinformationgiveninthepassage;N（forNO）ifthestatementcontradictstheinformationgiveninthepassage;NG（forNOTGIVEN）iftheinformationisnotgiveninthepassage.Forquestions8-10,completethesentenceswithinformationgiveninthepassage.WillWeRunOutofWater?Picturea“ghostship”sinkingintothesand,lefttorotondrylandbyarecedingsea.Thenimagineduststormssweepinguptoxicpesticidesandchemicalfertilizersfromthedryseabedandspewingthemacrosstownsandvillages.Seemlikeascenefromamovieabouttheendoftheworld?ForpeoplelivingneartheAralsea（咸海）inCentralAsia,it\'salltooreal.Thirtyyearsago,governmentplannersdivertedtheriversthatflowintotheseainordertoirrigate（providewaterfor）farmland.Asaresult,theseahasshrunktohalfitsoriginalsize,stranding（使搁浅）shipsondryland.Theseawaterhastripledinsaltcontentandbecomepolluted,killingall24nativespeciesoffish.Similarlarge——scaleeffortstoredirectwaterinotherpartsoftheworldhavealsoendedinecologicalcrisis,accordingtonumerousenvironmentalgroups.Butmanycountriescontinuetobuildmassivedamsandirrigationsystems,eventhoughsuchprojectscancreatemoreproblemsthantheyfix.Why?Peopleinmanypartsoftheworldaredesperateforwater,andmorepeoplewillneedmorewaterinthenextcentury.“Growingpopulationswillworsenproblemswithwater,”saysPeterH.Gleick,anenvironmentalscientistatthePacificInstituteforstudiesinDevelopment,Environment,andSecurity,aresearchorganizationinCalifornia.Hefearsthatbytheyear2025,asmanyasone——thirdoftheworld\'sprojected（预测的）8.3billionpeoplewillsufferfromwatershortages.WHEREWATERGOESOnly2.5percentofallwateronEarthisfreshwater,watersuitablefordrinkingandgrowingfood,saysSandraPostel,directoroftheGlobalWaterPolicyProjectinAmherst,Mass.Two——thirdsofthisfreshwaterislockedinglaciers（冰山）andicecaps（冰盖）.Infact,onlyatinypercentageoffreshwaterispartofthewatercycle,inwhichwaterevaporatesandrisesintotheatmosphere,thencondensesandfallsbacktoEarthasprecipitation（rainorsnow）.Someprecipitationrunsofflandtolakesandoceans,andsomebecomesgroundwater,waterthatseepsintotheearth.MuchofthisrenewablefreshwaterendsupinremoteplacesliketheAmazonriverbasininBrazil,wherefewpeoplelive.Infact,theworld\'spopulationhasaccesstoonly12,500cubickilometersoffreshwater—abouttheamountofwaterinLakeSuperior（苏必利尔湖）.Andpeopleusehalfofthisamountalready.“Ifwaterdemandcontinuestoclimbrapidly,”saysPostel,“therewillbesevereshortagesanddamagetotheaquatic（水的）environment.”CLOSETOHOMEWaterwoes（灾难）mayseemremotetopeoplelivinginrichcountriesliketheUnitedStates.ButAmericanscouldfaceseriouswatershortages,tooespeciallyinareasthatrelyongroundwater.Groundwateraccumulatesinaquifers（地下蓄水层），layersofsandandgravelthatliebetweensoilandbedrock.（Foreveryliterofsurfacewater,morethan90litersarehiddenunderground.）AlthoughtheUnitedStateshaslargeaquifers,farmers,ranchers,andcitiesaretappingmanyofthemforwaterfasterthannaturecanreplenish（补充）it.InnorthwestTexas,forexample,overpumpinghasshrunkgroundwatersuppliesby25percent,accordingtoPostel.Americansmayfaceevenmoreurgentproblemsfrompollution.DrinkingwaterintheUnitedStatesisgenerallysafeandmeetshighstandards.Nevertheless,oneinfiveAmericanseverydayunknowinglydrinkstapwatercontaminatedwithbacteriaandchemicalwastes,accordingtotheEnvironmentalProtectionAgency.InMilwaukee,400,000peoplefellillin1993afterdrinkingtapwatertaintedwithcryptosporidium（隐孢子虫），amicrobe（微生物）thatcausesfever,diarrhea（腹泻）andvomiting.THESOURCEWheresocontaminantscomefrom?Indevelopingcountries,peopledumpraw（未经处理的）sewage（污水）intothesamestreamsandriversfromwhichtheydrawwaterfordrinkingandcooking;about250millionpeopleayeargetsickfromwaterborne（饮水传染的）diseases.Indevelopedcountries,manufacturersuse100,000chemicalcompoundstomakeawiderangeofproducts.Toxicchemicalspollutewaterwhenreleaseduntreatedintoriversandlakes.（Certaincompounds,suchaspolychlorinatedbiphenyls（多氯化联二苯），orPCBs,havebeenbannedintheUnitedStates.）Butalmosteveryonecontributestowaterpollution.Peopleoftenpourhouseholdcleaners,carantifreeze,andpaintthinners（稀释剂）downthedrain;allofthesecontainhazardouschemicals.ScientistsstudyingwaterintheSanFranciscoBayreportedin1996that70percentofthepollutantscouldbetracedtohouseholdwaste.Farmershavebeencriticizedforoverusingherbicidesandpesticides,chemicalsthatkillweedsandinsectsbutinsectsbutthatpollutewateraswell.Farmersalsousenitrates,nitrogen——richfertilizerthathelpsplantsgrowbutthatcanwreakhavoc（大破坏）ontheenvironment.Nitratesaresweptawaybysurfacerunofftolakesandseas.Toomanynitrates“overenrich”thesebodiesofwater,encouragingthebuildupofalgae,ormicroscopicplantsthatliveonthesurfaceofthewater.Algaedeprivethewaterofoxygen