人教版選修六unit4《global warming》教案3

1、英語：Unit4Globalwarming教案（3）（新人教版選修6）Pre-reading,Reading,ComprehendingTeachingGoals:1.Toreadaboutglobalwarming.2.Togetsomeideaabouttheeffectofglobalwarming.3.Todevelopsomebasicreadingskills.TeachingProcedures:Step1.WarmingUpPurpose:ToarouseSsinterestinlearningaboutglobalwarming.1.TeamworkAnswertheques

2、tionsbelow:(1)Haveyoueverseenagreenhouse?(2)Howdoesagreenhousework?(3)Whatdoyouthinkgreenhousegases2.GroupworkLookatthepicture,andaskSssomedo?questions.T:Whatisthisbuildingmadeof?S1:Itsmadeofplastic.T:Whatsitspurpose?S2:Plantscangrowinitwhenitscoldoutside.T:Howdoesitwork?S3:Theglasstrapstheheatfromt

3、hesun,makingtheairwarmsothatplantsgrowbetter.Step2.Pre-readingPurpose:TogetSstolearnaboutgreenhousegases.11.GroupworkNowlookattheword“GREENHOUSEGASES”.Whatdoesitmean?Greenhousegases(GHG)aregaseouscomponentsoftheatmospherethatcontributetothegreenhouseeffect.Themajornaturalgreenhousegasesarewatervapor

4、,whichcausesabout36-70%ofthegreenhouseeffectonEarth(notincludingclouds):carbondioxide,whichcausesbetween9-26%;andozone,whichcausesbetween3-7%(notethatitisnotreallypossibletoassertthatsuch-and-suchagascausesacertainpercentageoftheGHE,becausetheinfluencesofthevariousgasesarenotadditive.Thehigherendsof

5、therangesquotedareforthegasalone;thelowerend,forthegascountingoverlaps).Naturallyoccurringgreenhousegasesincludewatervapor,carbondioxide,methane,nitrousoxide,andozone.Certainhumanactivities,however,addtothelevelsofmostofthesenaturallyoccurringgases.Verypowerfulgreenhousegasesthatarenotnaturallyoccur

6、ringincludehydrofluorocarbons(HFCs),perfluorocarbons(PFCs),andsulfurhexafluoride(SF6),whicharegeneratedinavarietyofindustrialprocesses.Eachgreenhousegasdiffersinitsabilitytoabsorbheatintheatmosphere.HFCsandPFCsarethemostheat-absorbent.2.IndividualworkGetSstoanswerthesequestionsindividually.Thenletth

7、emdiscusstheanswers.(1)Whowrotethemagazinearticle?Whatisthenameofthemagazine?2(2)Whatarethenamesofthethreescientistsmentionedinthearticle?(3)Whatdotheythinkaboutglobalwarming?Dotheyagreewithoneanother?(4)Whatarethetwographsabout?(5)Whatisthemaintopicofthearticle?Step3.Reading1.SkimmingPurpose:Togeta

8、briefunderstandingofthetext.Readthroughthetext,preferablythefirstandthelastsentencesofeachparagraphandwritethekeysentenceofeachparagraph.Keysentencesofeachparagraph:(1)Adebateoverwhetheritishumanactivitythathascausedtheglobalwarmingorwhetheritisjustanaturalphenomenon.(2)Manyscientistsbelievepeopleha

9、vecausedtheincreaseintheearthstemperature.(3)Theincreasedextraamountofcarbondioxidetrapsmoreheatenergycausingtheglobaltemperaturetogoup.(4)Thelevelsofcarbondioxidehaveincreasedgreatlyoverthelast100to150years.(5)Therearesomedifferentattitudestowardsthecausesofthisincreaseincarbondioxide.(6)Overthenex

10、t100yearstheamountofwarmingcouldbeaslowas1to1.5degreesCelsiusbutitcouldbeasmuchas5degreesCelsius.(7)Anincreaseoffivedegreeswouldbeacatastrophe.(8)Futurewarmingwouldcausethesealeveltorisebyseveralmeters.(9)Somepredictanywarmingwillbemildwithfewbadenvironmentalconsequences.(10)Morecarbondioxideisaposi

11、tivething.3(11)Nooneknowswhattheeffectsofglobalwarmingwillbe.2.ScanningPurpose:TogetSstohavesomedetailsinthetext.Readthearticlecarefully.Arethesestatementstrueorfalse?WriteaTforeachtruesentenceandanFforeachfalsesentence.(1)Thetemperaturelastcenturydidntincreasemuch.()(2)Everyonebelievesthatglobalwar

12、mingiscausedbytheactivitiesofhumans.()(3)JaniceFosterbelievesthatburningfossilfuelscausesglobalwarming.()(4)Naturalgasisagreenhousegas.()(5)Carbondioxideisabyproductofburningfossilfuels.()s(6)PeopleacceptCharlesKeelingdatabecausehetookaccuratemeasurements.()(7)Floodingcouldbeoneoftheeffectsoffutureg

13、lobalwarming.()(8)GeorgeHambleybelievesscientistsarejustguessingabouttheeffectsofglobalwarming.()(9)GerogeHambleyisworriedabouttheeffectsofcarbondioxideonplantgrowth.()(10)Itisclearwhattheeffectsofglobalwarmingwillbe.SuggestedAnswers:(1)F(2)F(3)T(4)F(5)T(6)T(7)T(8)T(9)F(10)F3.ListeningPurpose:Totrai

14、nSslisteningability.Listentothetapeandfollowitinalowvoice.4.GroupworkSsaredividedintofourgroups.Eachgroupissupposedtoreadthrougheach4partandthendiscussthem.Part1(Paragraph1)compare比較常見用法：comparewith把和比較Comparedwithhim,Ipareto把比作Lifeisoftencomparedtovoyage.(2)comeabout發(fā)生Howdiditcomeabout?那事是怎么發(fā)生的?常見詞

15、組：comeacross偶遇；碰到comeround恢復知覺，comealong進展；進行cometo涉及；到達；共計comeoutcomeupwith公開；問世；出版cometooneself恢復知覺想出(4)phenomenonn現(xiàn)象Itisonlyasocialphenomenon,butnotaphenomenonofnature.Part2(Paragraph2,3,4)fueln燃料Dontleavetheengineswitchedon.Itwastesfuel.拓展：fuelv加油；補給燃料Thecarisbeingfuelledreadytotrytobeatthespeed

16、record.(2)quantitiesof大量Largequantitiesofmoneyhavebeenspentonthebridge.拓展：alargequantityof大量的Heatealargequantityofnice.(3)perprep每;每一5Thefruitcosts30penceperkilo.Howmuchdoyouearnperweek?Part3(Paragraph5,6,7,8,9)(1)datan資料;數(shù)據(jù)Wehaventgotenoughdata.(2)resultin導致Theaccidentresultedinthedeathoftwopasseng

17、ers.Itresultedinsuccess.拓展：resultfrom由于Hisillnessresultedfromeatingbadfood.(3)catastrophen突如其來的大災難；大災禍Thewarwasaterriblecatastropheinwhichmanypeopledied.(4)climaten氣候Wehaveamildclimatehere.(5)consequencen結果；后果；影響Asaconsequenceofbeinginhospital,Shellydecidedthatshewantedtobecomeanurse.常見詞組：inconseque

18、nce因此，由此inconsequenceof由于的緣故(6)statevt陳述；說明Thebusmenhavestatedthatthestrikewillcontinueuntilgeneralagreementisreachedaboutpayandworkingconditions.(7)rangen&v6種類；范圍；幅度Thereisawiderangeoftemperature.氣溫變化很大。vi(在一定范圍內(nèi))變化Thenumberrangesbetween5and15.vt排列，整理Pleaserangethegoodsneatlyintheshopwindow.Part4(P

19、aragraph10)(1)buildup逐步建立；增加；增進Weneedtobuildupourreputation.Trafficisbuildinguponroadsintothecity.(2)Keepon繼續(xù)Pricekeptonincreasing.Hedidntstoprunning;hejustkepton.拓展：keepondoing與keepdoing的區(qū)別：keepondoing表示動作反復發(fā)生；keepdoing表示狀態(tài)或動作的持續(xù)。Hekeptonstandingupinclass.他在課堂上一再地站起來。Hekeptstandingthereforhalfanhou

20、rwithoutmoving.他一動不動地在那里站了半個小時。Step4.Post-readingPurpose:Tohaveadeepunderstandingofthetext.1.GroupworkNowyouaregoingtodiscussthestatement:Weshoulddonothingaboutglobalwarming.Followtheseinstructions:Getintogroupsofsix.Decidewhichthreeinyourgrouparegoingtoagreewiththestatement7(GroupA)andwhichthreeare

21、goingtodisagreewiththestatement(GroupB).(2)GroupAstudentsdiscusswhytheyagreewiththestatement;GroupBstudentsdiscusswhytheydisagree.(3)GroupsAandBgettogether.Theytelleachotherthereasonsforagreeingordisagreeingwiththestatement.2.IndividualworkAskSstoanswerthefollowingquestions.Presenttheiropinionstooth

22、erclassmates.(1)Whatdoyouthinkofglobalwarming?(2)Doyouthinkitserious?3.Discussion(1)Globalwarmingreferstoanaverageincreaseintheearthstemperature,whichinturncauseschangesinclimate.(2)Earthsclimatehasbeenchangingconstantlyoverits5-billion-yearhistory.(3)Theearthcouldbegettingwarmeronitsown.(4)Scientis

23、tsaresureaboutthegreenhouseeffect.TheyknowthatgreenhousegasesmaketheEarthwarmerbytrappingenergyintheatmosphere.(5)Withoutthegreenhouseeffect,theearthwouldnotbewarmenoughforhumanstolive.(6)Awarmerearthmayleadtochangesinrainfallpatterns,ariseinsealevel,andawiderangeofimpactsonplants,wildlife,andhumans.(7)Scientistsdontknowexactlywhatwillhappen