unit4阅读理解cet4补充题.ppt

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1、阅读理解Unit4补充题1（Para1)Therearehiddenfactorswhichscientistscall“feedbackmechanisms”.Nooneknowsquitehowtheywillinteractwiththechangingclimate.Here'soneexample:plantsandanimalsadapttoclimatechangeovercenturies.Atthecurrentestimateofhalfadegreecentigradeofwarmingperdecade,vegetation(植物)maynotkeepup.C

2、limatologistJamesHansenpredictsclimatezoneswillshifttowardthepolesby50to75kilometresayear-fasterthantreescannaturallymigrate.Speciesthatfindthemselvesinanunfamiliarenvironmentwilldie.The1000kilometre-widestripofforestrunningthroughCanada,theUSSRandScandinaviacouldbecutbyhalf.Millionsofdyingtree

3、swouldsoonleadtomassiveforestfires,releasingionsofCO2andfurtherboostingglobalwarming.(Para2)Therearedozensofotherpossible“feedbackmechanisms”.Highertemperatureswillfuelcondensationandincreasecloudiness,whichmayactuallydampdownglobalwarming.Others,likethe‘albedo’effect,willdotheopposite.The‘albe

4、do’effectistheamountofsolarenergyreflectedbytheearth'ssurface.Asnortherniceandsnowmeltsandthedarkerseaandlandpokesthrough,moreheatwillbeabsorbed,addingtotheglobaltemperatureincrease.(Para3)Evenifweweretomagicallystopallgreenhouse-gasemissionstomorrowtheimpactonglobalclimatewouldcontinuefordecad

5、es.Delaywillsimplymaketheproblemworse.Thefactisthatsomeofusaredoingquitewellthewaythingsare.Inthedevelopedworldprosperityhasbeenbuilton150yearsofcheapfossilfuels.(Para4)Materialprogresshasbeenlinkedtoenergyconsumption.Today75percentofalltheworld'senergyisconsumedbyaquarteroftheworld'spopulation

6、.Theaveragerichworldresidentaddsabout3.2tonsofCO2yearlytotheatmosphere,morethanfourtimestheleveladdedbyeachThirdWorldcitizen.TheUS,withjustsevenpercentoftheglobalpopulation,isresponsiblefor22percentofglobalwarming.1.“Feedbackmechanisms”inparagraph1mostprobablyreferto________.A.howplantsandanima

7、lsadapttohiddenfactorsB.howplantsandanimalsinteractwiththechangingclimateC.howclimatechangesD.howclimatezonesshift1.“Feedbackmechanisms”inparagraph1mostprobablyreferto________.A.howplantsandanimalsadapttohiddenfactorsB.howplantsan