大学英语四级模拟试卷一及参考答案

整理文档很辛苦,赏杯茶钱您下走!

免费阅读已结束,点击下载阅读编辑剩下 ...

阅读已结束,您可以下载文档离线阅读编辑

资源描述

句典翻译机单词不用背(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。ChoosinganOccupationPartIIReadingComprehension(SkimmingandScanning)(15minutes)Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,choosethebestanswerfromthefourchoicesmarked[A],[B],[C]and[D].Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.WillWeRunOutofWater?Picturea“ghostship”sinkingintothesand,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.He句典翻译机单词不用背’sprojected8.3billionpeoplewillsufferfromwatershortages.WhereWaterGoesOnly2.5percentofallwateronEarthisfreshwater,watersuitablefordrinkingandgrowingfood,saysSandraPostel,directoroftheGlobalWaterPolicyProjectinAmherst,Mass.Two-thirdsofthisfreshwaterislockedinglaciersandicecaps.Infact,onlyatinypercentageoffreshwaterispartofthewatercycle,inwhichwaterevaporatesandrisesintotheatmosphere,thencondensesandfallsbacktoEarthasprecipitation(rainorsnow).Someprecipitationrunsofflandtolakesandoceans,andsomebecomesgroundwater,waterthatseepsintotheearth.MuchofthisrenewablefreshwaterendsupinremoteplacesliketheAmazonriverbasininBrazil,wherefewpeoplelive.Infact,theworld’spopulationhasaccesstoonly12,500cubickilometersoffreshwater—abouttheamountofwaterinLakeSuperior.Andpeopleusehalfofthisamountalready.“Ifwaterdemandcontinuestoclimbrapidly,”saysPostel,“therewillbesevereshortagesanddamagetotheaquaticenvironment.”ClosetoHomeWaterwoesmayseemremotetopeoplelivinginrichcountriesliketheUnitedStates.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;about250million句典翻译机单词不用背(Certaincompounds,suchaspolychlorinatedbiphenyls,orPCBs,havebeenbannedintheUnitedStates.)Butalmosteveryonecontributestowaterpollution.Peopleoftenpourhouseholdcleaners,carantifreeze,andpaintthinnersdownthedrain;allofthesecontainhazardouschemicals.ScientistsstudyingwaterintheSanFranciscoBayreportedin1996that70percentofthepollutantscouldbetracedtohouseholdwaste.Farmershavebeencriticizedforoverusingherbicidesandpesticides,chemicalsthatkillweedsandinsectsbutthatpollutewateraswell.Farmersalsousenitrates,nitrogen-richfertilizerthathelpplantsgrowbutthatcanwreakhavocontheenvironment.Nitratesaresweptawaybysurfacerunofftolakesandseas.Toomanynitrates“overenrich”thesebodiesofwater,encouragingthebuildupofalgae,ormicroscopicplantsthatliveonthesurfaceofthewater.Algaedeprivethewat

1 / 30
下载文档,编辑使用

©2015-2020 m.777doc.com 三七文档.

备案号:鲁ICP备2024069028号-1 客服联系 QQ:2149211541

×
保存成功