大学基础英语教程第一册 Unit 8-text B.ppt

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1、Unit8TextBEnjoyEnglishVocabularyPracticeReadingAfterReadingBeforeReadingContentsBeforeReadingDiscussthefollowingquestionsinclass：1.Haveyoueverheardoftheterm“greenhouseeffect”?2.Asourworldisgettingwarmer,whatdoyouthinkishappeningtotheiceinAntarctica?SeaCreaturesinAntarcticaScientistsinvestigatingthe

2、icywatersofAntarcticasaidonTuesdaytheycollectedmysteriouscreaturesincludinggiantseaspidersandhugewormsfromthemurkydepths.Australianexpertstakingpartinaninternationalprogramtotakeacensusofmarinelifeinthesouthernoceancollectedspecimensfromupto6,500feetbeneaththesurface.1.GuessWhat?TheiceinwestAntarct

3、icaisgettingthicker.2.Inrecentyears,scientistshavebeenconcernedaboutglobalwarming.Theyworriedthathighertemperaturescouldturnthelargeicesheetstowater.Thiswouldcauseariseinsealevelsworldwideandchangetheweatheronearth.ReadingAntarcticIceGetsThickerChinese3.Thetheoryisnowbeingchallenged.Thissurprisingf

4、indingwaspublishedinAmericanmagazineScienceonJanuary18.ItwasmadewiththehelpofaCanadianmappingsatellite.Thesatelliteusedradartodeterminechangesintheicesheets.4.“Theicesheetsarelikeveryslowrivers,withiceflowingdown‘icestreams’,”saidIanJohns,ascientistfromalaboratoryinCalifornia,USA.5.Bystudyingthesat

5、elliteimages,Johnsfoundthattheicestreamshadslowedinthelast20years.Atpresent,snowisbuildingupontopoftheicesheetsfasterthantheriversaretakingitaway.ReadingChineseReadingChinese6.Inthepast,greenhousegaseswerethoughttobethinningAntarcticicesheets.Theseman-madegases,especiallycarbondioxide,areharmfultot

6、heatmosphere.7.ButJohnsbelievesothernaturalforcesarecreatingchangesinAntarctica.8.“Ithinkinthiscaseit’sremovedfromglobalwarming,”hesaid.“Icesheetsrunontheirowntime.”ReadingChinese9.Tomakemattersevenmoredifficult,globalwarmingcancauseicesheetstogrow.Thewarmertheyget,themorewatergoesintotheatmosphere

7、,andthemoresnowfallsoverthepolaricecaps.10.Someexpertshaveevensuggestedthatwhatbeginsasglobalwarmingwillstartanothericeageonearth.11.ThescientistssaidwestAntarcticaistheonlycontinentthatiscooling.Inotherpar