Unit 4 Exploring plants Period 1 Warming Up，Pre­reading & Reading 课件.ppt

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1、Unit4ExploringplantsPeriod1WarmingUp，Prereading&Reading课件THEDESTRUCTIONOFTROPICALRAINFORESTSEdWalker(E)isinterviewingDrAnneButler(A)aboutthedestructionoftropicalrainforests.E：Anne，wehearalotthesedaysabouthowquicklytropicalrainforestsaredisappearing.A：Yes，that'srig

2、ht.Rainforestsnowcoveronly6%oftheearth'slandsurface.Theyusedtocoverabout14%，somorethanhalfoftheworld'stropicalrainforestshavebeendestroyed，andthat'sinlessthan50years.Over150acresofrainforestislosteveryminuteinAsia，Africa，CentralandSouthAmerica.E：That'sunbelievable

3、.A：Yes，it'sfrightening.Thelastremainingrainforestscouldbegoneinlessthan40years.E：Butwhyisthishappening?A：Well，thereareanumberofreasons.Aspopulationsincrease，peopleneedmorelandtoliveon.Forestsarecutdowntoplantcropsortostartfarms.Thewoodissoldforfirewoodorbuildingma

4、terials，furnitureandpaper，forexample.Andtherearealsominingcompanieswhichdestroytheforestsintheirsearchforminerals.E：Isupposepeoplehavetomakealiving.A：Yes，butyouknow，peoplecanmakemoremoneybyharvestingthingslikefruits，nutsandoils，aswellasplantsthatcanbeusedinmedicin

5、ethanbycuttingdowntheforests.E：Ohreally？Ididn'tknowthat.Now，couldyououtlinesomeofthereasonswhyit'snotagoodideatodestroyrainforests?A：Sure.Youmusthaveheardabouttherichanimalandplantlifeintropicalrainforests.Well，thereareabout10millionspeciesofplantsandanimalsinthew

6、orld.Morethanhalfoftheseliveinthetropicalrainforests.So，destroyingrainforestsmeansthatthousandsofthesespeciesaredyingoutbeforewe'veevenrealizedit.E：I'veheardtoothattherainforestcouldprovideuswithcuresfordiseases.A：Yes，therearecertainlymanynewdrugswaitingtobediscov

7、ered.Anotherproblemisthatthedestructionofforestscontributestoglobalwarming.Also，rainforestsabsorbalotofrainsothatthere'saconstantsupplyofcleanwaterrunningintoriversandlakes.Ifthetreesarecutdown，therainisn'tabsorbedandthereisflooding.E：So，whatcanindividualsdotohelp

8、slowdownthedestruction?A：That'sagoodquestion...(fadeout)阅读短文，判断正(T)误(F)1．Rainforestscover14%oftheearth'slandsurface.()2．Morethanhalfoftherainforestshave