安徽省滁州市第二中学高中英语 Unit22 Environmental Protection T.docx

安徽省滁州市第二中学高中英语 Unit22 Environmental Protection T.docx

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安徽省滁州市第二中学高中英语Unit22EnvironmentalProtectionT

安徽省滁州市第二中学高中英语Unit22EnvironmentalProtectionTheSecondPeriodLesson1GlobalWarming教案北师大版选修8

Teachinggoals教学目标

1.TargetLanguage目标语言

a.重点词汇和短语

consensus,beyond,relevant,refer,bounce,pin,coincidence,condemn,federal,reservation,sacrifice,advocate,recycle,substitute,beyondone’scontrol,takeaction,aheadof

b.重点句子

Inthelastfewdecades,scientistshavereachedconsensusandreportedthathumanbeingsarecausingchangesintheEarth’sclimate—somethingpreviouslyseenasbeyondourcontrol.

2.Abilitygoals能力目标

Learnwhatglobalwarmingisandenablestudentstolearnitscausesandconsequences.

3.Learningabilitygoals学能目标

Byreadinganarticlehelpstudentstolearnhowtheycanhelpsolvetheproblemofglobalwarming.

Teachingimportantpoints教学重点

Whathumanactivitiesarecausingglobalwarmingandhowwecanhelpsolvetheproblemofglobalwarming.

Teachingdifficultpoints教学难点

Howwecanhelpsolvetheproblemofglobalwarming.

Teachingmethods教学方法

Listening,reading,discussing.

Teachingaid教具准备

Multimediacomputer.

Teachingprocedures&ways过程与方式

StepILeadingin

Inthisprocedurestudentswilltalkaboutthecausesandconsequencesofglobalwarming.Beginthelessonbyaskingstudentstodiscussthequestionsinbeforeyoustart

T:

YesterdaywelearnedfromthepassageinCultureCornerthatgasesfromburningcoalandoilarethemajorcausesofglobalwarming.Didyoumakeyoursurveyonhowstudentscometoschool?

S1:

Iasked40students.Teninthefortycometoschoolbybus.Twenty-oneridebicycles.Eightofthefortytakeacarandonlyonewalkstoschool.

...

T:

Fromthesurveyyoumadewecanseemostofstudentsinourschooltakeagreenwaytoschool.I’mgladwearenothavingsomanycars.Becausegasespumpedintotheatmospherefromcarswillspeedupglobalwarming.Haveyounoticedthatin2006wehadaverywarmwinter?

ExpertssayglobalwarminghaschangedtheclimateinChina.Inthisclasswearegoingtolearnmoreaboutglobalwarming.Wewillreadanarticle“Canwetaketheheat?

”Beforewestartthetext,pleasediscussthequestioninBeforeyoustart.

StepIIBeforeyoustart

DiscussthetwoquestionsinBeforeyoustartandworkoutthemeaningsofthegivenwords.

T:

OK,openyourbooksanddiscussthequestioninBeforeyoustartonPage6.Whichcountriesdoyouthinkcontributemoretoglobalwarming,developedcountriesordevelopingcountries?

Ss:

Developedcountries.Becausetheyhavemorecarsandfactoriesandgasesfromcarsandfactoriesarethemajorcauseofglobalwarming.

T:

Goodanswer.PleasescanthetextforthegivenwordsinEx2andtrytoworkouttheirmeaning.

Whilestudentsarediscussingthewords,Teachershouldwalkaroundtheclassroomandgivenecessaryhelpwhenneeded.

Severalminuteslater,askstudentstopresenttheiranswerseitherinEnglishorChinese.Studentsmayevenbeencouragedtoexplainthemeaningsusingpictures.ShowthesuggestedanswersonthePowerPoint.

StepIIIReadtolearn

Dealwiththereadingpart.

Scanning

Askstudentstoscanthetextandfindwhatexactlyglobalwarmingis.

T:

WhatisthetitleofLesson1?

Ss:

GlobalWarming.

T:

Doyouknowwhatexactlyglobalwarmingis?

Pleasescanthetextandfindtheanswerinthetext.

Ss:

GlobalwarmingreferstoanaverageincreaseintheEarth’stemperature.

T:

Quitegood!

Thenskimthetextandfindwhathumanactivitiesarecausingglobalwarming.

S:

Asaresultofincreasedindustry,agriculture,thecuttingdownofforests,theincreaseintransportandtheburningoffuels,nearly6tonesofcarbondioxidegoesintotheatmosphereeveryyearforeveryoneoftheEarth’s6billionpeople.Overthelast100years,theglobalaveragetemperaturehasincreasedby1°F.Ifwecontinuetoproducecarbondioxideandothergasesinsuchquantities,wearecondemninglifeonEarthandshouldexpectsevereconsequences.

Skimming

ShowthefollowingformonthePowerPointandaskthemtoworkingroupsandcompletetheform.

term

definition

causes

consequences

howtosolvetheproblem

Globalwarming

Fiveminuteslater,showthesuggestedanswersonthePowerPoint.

term

definition

causes

consequences

howtosolvetheproblem

Globalwarming

referstoanaverageincreaseintheEarth’stemperature.

Whengreenhousegasesintheatmosphereincrease,moreheatistrapped.（thegreenhouseeffect）

TheEarth’stemperaturerises.

Government’sactionandeachpersonshouldplaytheirpart（smallchangesmadebyeveryoneworldwide）.

AskstudentstoskimthetextandthenfinishEx3onPage7.Studentsmaydiscussthequestionsingroups.

T:

LookthroughthequestionsinEx3onPage7first.Thenskimthetexttofindtheanswers.

Thenchecktheanswerswiththewholeclass.

Suggestedanswers:

1.GlobalwarmingisanaverageincreaseintheEarth’stemperature.

2.Increasedindustry,agriculture,thecuttingdownofforests,theincreaseintransportandtheburningoffuelsarecausingglobalwarming.

3.By1°F.

4.Yes,theyare.BecausegreenhousegasestrapheatfromthesunintheEarth’satmosphere.Otherwisetheearthwouldbeverycoldandunsuitableforlife.

5.Wecantakepublictransport,recycling,usinglow-flowshowerheads,buyingefficientlightbulbstostopglobalwarming.

StepIVExplanation

Duringthisprocedureteacherwillplaythetapeforstudents.Studentswillunderlinethedifficultsentences.Afterlisteningtothetape,Teacherwillexplainthetextanddealwithlanguageproblems.

T:

Afterdoingthecomprehensionofthetext,let’sdealwithsomedifficultlanguagefocuses.NowIwillplaythetapeforyou.Pleasemakeamarkwhereyouhavedifficulties.

Afterlisteningtothetape,explainthedifficultsentencestostudents.Beforeexplainingthedifficultpoints,studentsareaskedtorefertothenotestothetextonpage114.

T:

Doyouhaveanydifficultieswiththetext？

S1:

Couldyoupleaseexplainthesecondparagraphtous?

T:

Thesecondparagraphtellsustheassociationgreenhousegaseshavewithglobalwarming.The“greenhouseeffect”oftengetsabadrapbecauseofitsassociationwithglobalwarming,butthetruthiswecouldn’tlivewithoutit.Lifeonearthdependsonenergyfromthesun.About30percentofthesunlightthatbeamstowardEarthisdeflectedbytheouteratmosphereandscatteredbackintospace.Therestreachestheplanet’ssurfaceandisreflectedupwardagainasatypeofslow-movingenergycalledinfraredradiation.

Asinfraredradiationiscarriedaloftbyaircurrents,itisabsorbedby“greenhousegases”suchaswatervapor,carbondioxide,ozoneandmethane,whichslowsitsescapefromtheatmosphere.

Althoughgreenhousegasesmakeuponlyabout1percentoftheEarth’satmosphere,theyregulateourclimatebytrappingheatandholdingitinakindofwarm-airblanketthatsurroundstheplanet.Thisphenomenoniswhatscientistscallthe"greenhouseeffect."Withoutit,scientistsestimatethattheaveragetemperatureonEarthwouldbecolderbyapproximately30degreesCelsius（54degreesFahrenheit）,fartoocoldtosustainourcurrentecosystem.

WhilethegreenhouseeffectisanessentialenvironmentalprerequisiteforlifeonEarth,therereallycanbetoomuchofagoodthing.

Theproblemsbeginwhenhumanactivitiesdistortandacceleratethenaturalprocessbycreatingmoregreenhousegasesintheatmospherethanarenecessarytowarmtheplanettoanidealtemperature.

Today,theincreaseintheEarth’stemperatureisincreasingwithunprecedentedspeed.Tounderstandjusthowquicklyglobalwarmingisaccelerating,considerthis:

Duringtheentire20thcentury,theaverageglobaltemperatureincreasedbyabout0.6degreesCelsius（slightlymorethan1degreeFahrenheit）.

Usingcomputerclimatemodels,scientistsestimatethatbytheyear2100theaverageglobaltemperaturewillincreaseby1.4degreesto5.8degreesCelsius（approximately2.5degreesto10.5degreesFahrenheit）.

Nowpleasereadthefirstsentenceinthesecondparagraph.What’sthefunctionofthat-clause?

S1:

Itisanattributiveclausemodifying‘anaverageincrease’.

T:

Good!

‘that’refersto‘anaverageincreaseintheEarth’stemperature’.FromthissentencewecanlearnanaverageincreaseintheEarth’stemperaturewillcauseclimatechanges.Inthesecondsentencethereisalsoanattributiveclausecausedby‘which’.Whatdoes‘which’referto?

S2:

‘Which’referstogreenhousegases.

T:

Right!

GreenhousegasestrapheatfromthesunintheEarth’satmosphere.Withoutgreenhousegases,theearthwouldbeverycoldandimpossibleforlife.Doyouhaveanyotherquestions?

S2:

No.

T:

Therearemanyusefulphrasesinthetext.Pleasesumupthephrasesandthenwewillanalyzethetext.

StepVPractice

DealwithEx5onpage7.Askstudentstodotheexercisesindividually.Whiledoingtheexercises,remindstudentsthattheyshouldpayattentiontothecorrectformofthegivenwords.Makenecessarychangeswhereneeded.Thenchecktheanswerswiththewholeclass.

StepVIAnalyzingthetext

Helpstudentsanalyzethestructureofthetext.Askstudentstodiscussingroupsandlatereachgroupwillspeakouttheiropinions.Afterthis,showthesuggestedanswersonthePowerPoint.

T:

OK.Let’sreadthetextagain.Pleaselookatthestructureofthetext.Youaregiven5minutes.

…

T:

Pleasestophere.I’mgladyouthoughtactivelyandhadaheateddiscussion.Whatisitswritingstyle?

Ss:

Thistextisanexpositorywriting.

T:

Whatisthetopicofthetext?

Whatisthetextabout?

S1:

Globalwarming.

S2:

Thetextintroduceswhatglobalwarmingis.

S3:

Itscausesandconse