雅思阅读真题.docx

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1、雅思阅读真题雅思阅读真题还在为雅思考试熬夜奋战的小伙伴们看过来!为了帮助你们更好进行复习,店铺特地整理了历年考试结束后网友的真题回忆,希望大家通过自己的努力最终拿下满意的成绩!一、考试概述本次考试的文章是三篇旧文章,难度中等。包含考古科学、生物科学以及商业三个领域的文章。二、具体题目分析Passage1题目:Aheadofthetime题号:旧题参考文章:MammothKi11MammothisanyspeciesoftheextinctgenusMammothszproboscideanscommon1yequippedwith1ong,curvedtusksandinnorthernspe

2、cies,acoveringof1onghair.They1ivedfromthePtioceneepochfromaround5mi11ionyearsagozintotheHotoceneatabout4,500yearsago,andweremembersofthefami1yE1ephantidaezwhichcontains,a1ongwithmammoths,thetwogeneraofmoderne1ephantsandtheirancestors.A1iketheirmodernre1atives,mammothswerequite1arge.The1argestknownsp

3、eciesreachedheightsintheregionof4mattheshou1derandweightsupto8tonneszwhi1eexceptiona11y1argema1esmayhaveexceeded12tonnes.However,mostspeciesofmammothwereon1yaboutas1argeasamodem.Asiane1ephant.Bothsexesboretusks.Afirst,sma11setappearedatabouttheageofsixmonthsandthesewererep1acedatabout18monthsbythepe

4、rmanentset.Growthofthepermanentsetwasatarateofabout1to6inchesperyear.Basedonstudiesoftheirc1osere1atives,themodeme1ephants,mammothsprobab1yhadagestationperiodof22months,resu1tinginasing1eca1fbeingborn.Theirsocia1structurewasprobab1ythesameasthatofAfricanandAsiane1ephants,withfema1es1ivinginherdshead

5、edbyamatriarchzwhi1sthu11s1ivedso1itary1ivesorformed1oosegroupsaftersexua1maturity.BMEXICOCITY-AIthoughitshardtoimagineinthisageofurbanspraw1andautomobi1es.NorthAmericaoncebe1ongedtomammoths,came1s,grounds1othsas1argeascowszbear-sizebeaversandotherformidab1ebeasts.Some11z000yearsago,however;these1ar

6、gebodiedmamma1sandothers-about70speciesina11-disappeared.Theirdemisecoincidedrough1ywiththearriva1ofhumansintheNewWor1danddramaticc1imaticchange-factorsthathaveinspiredsevera1theoriesaboutthedieoff.Yetdespitedecadesofscientificinvestigation,theexactcauseremainsamystery.Nownewfindingsoffersupporttoon

7、eofthesecontroversia1hypotheses:thathumanhuntingdrovethismegafauna1menagerie(巨型动物兽群)toextinction.Theoverki11mode1emergedinthe1960s,whenitwasputforthbyPau1S.MartinoftheUniversityofArizona.Sincethen,criticshavechargedthatnoevidenceexiststosupporttheideathatthefirstAmericanshuntedtotheextentnecessaryto

8、causetheseextinctions.Butattheannua1meetingoftheSocietyofVertebratePa1eonto1ogyinMexicoCity1astOctober;pa1eoeco1ogistJohnA1royoftheUniversityofCa1iforniaatSantaBarbaraarguedthat,infacthunting-drivenextinctionisnoton1yp1ausib1e,itwasunavoidab1e.Hehasdetermined,usingacomputersimu1ationthatevenaverymod

9、estamountofhuntingwou1dhavewipedtheseanima1sout.CAssuminganinitia1humanpopu1ationof100peop1ethatgrewnomorethan2percentannua11y,A1roydeterminedthatifeachbandOfsayz50peop1eki11ed15to201argemamma1sayear;humanscou1dhavee1iminatedtheanima1popu1ationswithin1r000years.1argemamma1sinparticu1arwou1dhavebeenv

10、u1nerab1etothepressurebecausetheyhave1ongergestationperiodsthansma11ermamma1sandtheiryoungrequireextendedcare.DNoteveryoneagreeswithA1royxsassessment.Foroneztheresu1tsdependinpartonpopu1ation-sizeestimatesfortheextinctanima1s-figuresthatarenotnecessari1yre1iab1e.Butamorespecificcriticismcomesfrommam

11、mo1ogistRossD.E.MacPheeoftheAmericanMuseumofNatura1HistoryinNewYorkCity,whopointsoutthatthere1evantarchaeo1ogica1recordcontainsbare1yadozenexamp1esofstonepointsembeddedinmammothbones(andnone,itshou1dbenoted,areknownfromothermegafauna1remains)-hard1ywhatonemightexpectifhuntingdrovetheseanima1stoextin

12、ction.Furthermore,someofthesespecieshadhugerangesthegiantJeffersonsgrounds1othzforexamp1e,1ivedasfarnorthastheYukonandasfarsouthasMexicowhichwou1dhavemades1aughteringtheminnumberssufficienttocausetheirextinctionratherimp1ausib1e,hesays.EMacPheeagreesthathumansmost1ike1ybroughtabouttheseextinctions(a

13、swe11asothersaroundthewor1dthatcoincidedwithhumanarriva1),butnotdirect1y.Ratherhesuggeststhatpeop1emayhaveintroducedhyper1etha1disease,perhapsthroughtheirdogsorhitchhikingvermin,whichthenspreadwi1d1yamongtheimmuno1ogica11ynaivespeciesoftheNewWor1d.Asintheoverki11mode1,popu1ationsof1argemamma1swou1dh

14、aveahardertimerecovering.Repeatedoutbreaksofahyperdiseasecou1dthusquick1ydrivethemtothepointofnoreturn.SofarMacPheedoesnothaveempirica1evidenceforthehyperdiseasehypothesis,anditwontbeeasytocomeby:hyper1etha1diseasewou1dki11fartooquick1yto1eaveitssignatureonthebonesthemse1ves.Buthehopesthatana1ysesof

15、tissueandDNAfromthe1astmammothstoperishW川eventua11yrevea1murderousmicrobes.FThethirdexp1anationforwhatbroughtonthisNorthAmericanextinctiondoesnotinvo1vehuman,beings.Instead,itsproponentsb1amethe1ossontheweather.TheP1eistoceneepochwitnessedconsiderab1ec1imaticinstabi1ity,exp1ainspa1eonto1ogistRusse11

16、W.GrahamoftheDenverMuseumofNatureandScience.Asaresu1t,certainhabitatsdisappeared,andspeciesthathadonceformedcommunitiessp1itapart.Forsomeanima1s,thischangebroughtopportunity.Formuchofthemegafaunazhowever,theincreasing1yhomogeneousenvironment1eftthemwithshrinkinggeographica1ranges-adeathsentencefor1argeanima1s,whichneed1argeranges.A1thoughthesecreaturesmanagedtomaintainviab1epopu1ationsthroughmostoftheP1eistocene,thefina1majorf1uctuation-theso-ca11

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