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1、以下，是这次环球托福为正在进行托福备考的考友们整理了托福TPO24阅读真题及答案LakeWater。我们建议考友们，先做真题，后看答案进行验证自己的正确率。之后，环球托福还会进一步推出托福TPO24阅读真题的做题思路讲解分析，做完真题后，更便于提高托福阅读能力。托福TPO24阅读真题LakeWaterLakeWaterWheredoesthewaterinalakecomefrom,andhowdoeswaterleaveit?Waterentersalakefrominflowingrivers,fromunderwaterseepsandsprin
2、gs,fromoverlandflowoffthesurroundingland,andfromrainfallingdirectlyonthelakesurface.Waterleavesalakeviaoutflowingrivers,bysoakingintothebedofthelake,andbyevaporation.Somuchisobvious.Thequestionsbecomemorecomplicatedwhenactualvolumesofwaterareconsidered:howmuchwaterentersandleave
3、sbyeachroute?Discoveringtheinputsandoutputsofriversisamatterofmeasuringthedischargesofeveryinflowingandoutflowingstreamandriver.Thenexchangeswiththeatmospherearecalculatedbyfindingthedifferencebetweenthegainsfromrain,asmeasured(ratherroughly)byraingaugesandthelossesbyevaporation
4、,measuredwithmodelsthatcorrectfortheothersourcesofwaterloss.Forthemajorityoflakes,certainlythosesurroundedbyforests,inputfromoverlandflowistoosmalltohaveanoticeableeffect.Changesinlakelevelnotexplainedbyriverflowsplusexchangeswiththeatmospheremustbeduetothenetdifferencebetweenwh
5、atseepsintothelakefromthegroundwaterandwhatleaksintothegroundwater.Notetheword"net":measuringtheactualamountsofgroundwaterseepageintothelakeandoutofthelakeisamuchmorecomplicatedmatterthanmerelyinferringtheirdifference.Onceallthisinformationhasbeengathered,itbecomespossibletojudg
6、ewhetheralake’sflowismainlyduetoitssurfaceinputsandoutputsortoitsundergroundinputsandoutputs.Iftheformeraregreater,thelakeisasurface-water-dominatedlake;ifthelatter,itisaseepage-dominatedlake.Occasionally,commonsensetellsyouwhichofthesetwopossibilitiesapplies.Forexample,apondinh
7、illycountrythatmaintainsasteadywaterlevelallthroughadrysummerinspiteofhavingnostreamsflowingintoitmustobviouslybeseepagedominated.Conversely,apondwithastreamflowinginoneendandouttheother,whichdriesupwhenthestreamdriesup,isclearlysurfacewaterdominated.Bywhatevermeans,alakeisconst
8、antlygainingwaterandlosingwater:itswaterdoesnot
