TPO24阅读文本题目答案

时间：2025-03-10

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Contents

TPO软件免费版下载..............................................................................................2LakeWater..............................................................................................................3QuestionsforPassage1..........................................................................................5Passage2:BreathingDuringSleep..........................................................................9QuestionsforPassage2........................................................................................11Passage3.MovingintoPueblos............................................................................15QuestionsforPassage3........................................................................................17

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LakeWater

<1>◆</1>Wheredoesthewaterinalakecomefrom,andhowdoeswaterleaveit?Waterentersalakefrominflowingrivers,fromunderwaterseepsandsprings,fromoverlandflowoffthesurroundingland,andfromrainfallingdirectlyonthelakesurface.Waterleavesalakeviaoutflowingrivers,bysoakingintothebedofthelake,andbyevaporation.[1]Somuch[/1]isobvious.

<2>◆</2><3>◆</3><4>◆</4>Thequestionsbecomemorecomplicatedwhenactualvolumesofwaterareconsidered:howmuchwaterentersandleavesbyeachroute?Discoveringtheinputsandoutputsofriversisamatterofmeasuringthedischargesofeveryinflowingandoutflowingstreamandriver.Thenexchangeswiththeatmospherearecalculatedbyfindingthedifferencebetweenthe[2]gains[/2]fromrain,asmeasured(ratherroughly)byramgauges,andthelossesbyevaporationmeasuredwithmodelsthatcorrectfortheothersourcesofwaterloss.Forthemajorityoflakescertainlythosesurroundedbyforests,inputfromoverlandflowistoosmalltohaveanoticeableeffect.Changesinlakelevelnotexplainedbyriverflowsplusexchangeswiththeatmospheremustbeduetothenetdifferencebetweenwhatseepsintothelakefromthegroundwaterandwhatleaksintothegroundwater.[4]Notetheword"net":[/4]measuringtheactualamountsofgroundwaterseepageintothelakeandoutofthelakeisamuchmorecomplicatedmatterthanmerelyinferringtheirdifference.

<5>◆</5><6>◆</6><13>◆</13>Onceallthisinformationhasbeengathered,itbecomespossibletojudgewhetheralake'sflowismainlyduetoitssurfaceinputsandoutputsortoitsundergroundinputsandoutputs.{13}█{/13}Iftheformeraregreater,thelakeisasurface-water-dominatedlake;ifthelatter,itisaseepage-dominatedlake.{13}█{/13}Occasionally,commonsensetellsyouwhichofthesetwopossibilitiesapplies.{13}█{/13}Forexample,apondinhillycountrythatmaintainsasteadywaterlevelallthroughadrysummerinspiteofhavingnostreamsflowingintoitmustobviouslybeseepagedominated[5].Conversely[/5],apondwithastreamflowinginoneendandouttheother,whichdriesupwhenthestreamdriesup,isclearlysurfacewaterdominated.{13}█{/13}

<7>◆</7>Bywhatevermeans,alakeisconstantlygainingwaterandlosingwater:itswaterdoesnotjustsitthere,or,anyway,notforlong.Thisraisesthematterofalake'sresidencetime.Theresidencetimeistheaveragelengthoftimethatanyparticularmoleculeofwaterremainsinthelake,anditiscalculatedbydividingthevolumeofwaterinthelakebytherateatwhichwater

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leavesthelake.Theresidencetimeisanaverage;thetimespentinthelakebyagivenmolecule(ifwecouldfollowitsfate)woulddependontherouteittook:itmightflowthroughaspartofthefastest,mostdirectcurrent,oritmightcircleinabackwaterforanindefinitelylongtime

<8>◆</8><9>◆</9>Residencetimesvaryenormously.Theyrangefromafewdaysforsmalllal.esuptoseveralhundredyearsforlargeones:LakeTahoe,inCalifornia,hasaresidencetimeof700years.TheresidencetimesfortheGreatLal.esofNorthAmerica,namely,Lal.esSuperior,Michigan.Huron,Erie,andOntario,are,respectively,190,100,22,2.5,http://keErie'sisthelowest:althoughitsareaislargerthanLakeOntario's,itsvolumeislessthanone-thirdasgreatbecauseitissoshallow-lessthan20metersonaverage.

<10>◆</10><11>◆</11><12>◆</12>Agivenlake'sresidencetimeisbynomeansafixedquantity.Itdependsontherateatwhichwaterentersthelake,andthatdependsontherainfallandtheevaporationrate.Climaticchange(theresultofglobalwarming?)isdramaticallyaffectingtheresidencetimesofsomelakesinnorthwesternOntario.Canada.Intheperiod1970to1986,rainfallintheareadecreasedfrom1,000millimetersto650millimetersperannum,whileabove-averagetemperaturesspeededuptheevapotranspirationrate(therateatwhichwaterislosttotheatmospherethroughevaporationandtheprocessesofplantlife).Theresulthasbeenthattheresidencetimeofoneofthela4.esincreasedfrom5to18yearsduringthestudyperiod.Theslowingdownofwaterrenewalleadstoachainof[10]further[/10]consequences:itcausesdissolvedchemicalstobecomeincreasinglyconcentrated,andthis,inturn,hasamarledeffectonalllivingthingsinthelake.

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QuestionsforPassage1

RightAnswer:4

1.Thephrase“Somuch”inthepassagerefersto

thenegativeeffectsofoverlandflow,ram,andevaporationonriverwaterlevels

waterthatalakelosestooutflowingrivers.tothelakebed,andtoevaporation

theimportanceofriverstothemaintenanceoflakewaterlevels

theinformationgivenaboutwaysthatwatercanenterorexitalakeRightAnswer:2

2.Theword"gains"inthepassageisclosestinmeaningto

results

increases

resources