Unit4　Globalwarming本单元的中心话题是人类当今面临的环境问题，主要探讨了“全球变暖”和“节约能源”等方面的问题。由于人类过多使用不可再生能源，大气中二氧化碳的含量逐年增加，导致全球气温上升。通过学习本单元，让学生了解能源分为“不可再生能源”和“可再生能源”，帮助学生树立“节约能源、保护环境”的主人翁意识。本单元的主要教学内容如下表所示：类别课程标准要求掌握的内容话题Globalwarming，pollutionandtheimportanceofprotectingtheearth[来源:学|科|网][来源:学科网][来源:学_科_网Z_X_X_K][来源:学科网ZXXK]词汇tend[来源:学|科|网]v.趋向；易于；照顾catastrophen.大灾难；浩劫opposev.反对；反抗；与(某人)较量floodn.洪水；水灾statev.陈述；说明consequencen.结果；后果；影响glancev.看一下；扫视　n．一瞥existencen.生存；存在quantityn.量；数量commitmentn.承诺；交托；信奉rangen.种类；范围pollutionn.污染；弄脏tendencyn.趋向；趋势growthn.增长；生长circumstancen.环境；情况motorn.发动机opposedadj.反对的，对立的cann.容器；罐头steadyadj.平稳的；持续的microwaven.微波炉；微波widespreadadj.分布广的；普遍的educatorn.教育工作者；教育家averageadj.平均的contributionn.贡献consumev.消费；消耗；耗尽；吃完presentationn.显示；演出subscribev.同意；捐赠；订阅disagreementn.分歧；不一致advocatev.拥护；提倡；主张randomadj.胡乱的；任意的refreshv.使恢复；使振作mildadj.温和的；温柔的；淡的graphn.图表；坐标图；曲线图outeradj.外部的phenomenonn.现象electricaladj.电的；与电有关的fueln.燃料casualadj.随便的；偶然的datan.资料；数据nuclearadj.核的；核能的trendn.趋势；倾向perprep.每；每一comeabout发生；造成keepon继续subscribeto同意；赞成；订购onthewhole大体上；基本上quantitiesof大量的onbehalfof代表……一方；作为……7,的代言人goup上升；增长；升起putupwith忍受；容忍resultin导致solongas只要beopposedto反对andsoon等等evenif即使greenhouseeffect温室效应句型1....it_ishumanactivitythathascausedthisglobalwarming...　(emphatic“it”)2....itisarapidincreasewhen_compared_toothernaturalchanges.(ellipsis)3.Thereisnodoubtthat_the_earth_is_becoming_warmer...(theappositiveclause)4.Withoutthe“greenhouseeffect”，theearthwould_beaboutthirty－threedegreesCelsiuscoolerthanitis.(thesubjunctivemood)功能1.同意与不同意(Agreementanddisagreement)Exactly.You'reright.　　　　Iagree.　　　　That'scorrect/true/right.I'mafraidIdisagreewithyou.I'mafraidnot.Idon'tthinkso.Noway.Idon'tagree.Idoubt...2．责备与抱怨(Blameandcomplaint)I'msorrytobringthisup，but...　　　I'msorrytohavetosaythis，but...Theyshouldn'thavedoneit.Theyaretoblame.Perhaps/Maybetheyshould/oughtto...Whydon'tyoudosomethingaboutit？语法“it”的用法(theuseof“it”)(2)...it_ishumanactivitythathascausedthisglobalwarming...教学重点1.Getstudentstoknowaboutglobalwarminganditseffect；torealizewhatwecandoaboutglobalwarming.2．Havestudentslearnsomeusefulnewwordsandexpressionsaboutglobalwarmingandletthemlearneffectivewaystomasterthem.3．Enablestudentstograspandusetheexpressionsofagreementanddisagreement，blameandcomplaint.4．Letstudentslearnthenewgrammaritem：theuseof“it”(2)．5．Developstudents'listening，speaking，readingandwritingability.教学难点1.Enablestudentstomastertheuseof“it”(2)．2．Letstudentslearntowriteashortpassagetotellothershowtosolvetheproblemofglobalwarming.3．Developstudents'integrativeskills.课时安排Periodsneeded：6Period1　WarmingUp，Pre－reading，ReadingandComprehendingPeriod2　LanguageStudyPeriod3　Grammar—theUseof“It”(2)Period4　ListeningandSpeakingPeriod5　ReadingandWritingPeriod6　SummingUp，LearningTipandAssessment7,Period1　WarmingUp，Pre－reading，ReadingandComprehending教学内容分析　　　Thisisthefirstteachingperiodofthisunit.Thecentralpartofthisperiodisthereadingpassagewiththetitleof“TheEarthIsBecomingWarmer—ButDoesItMatter？”talkingabouttheglobalissuewhichhasagreateffectonhumanbeings'life.WarmingUpgivessixpicturestohelpstudentslistthesourcesofenergytheycanthinkofinourdailylife.Thentheywillbeledtodiscusswhichenergysourceis“renewable”andwhichis“non－renewable”．Thispartisdesignedtohelpthestudentstorecalltheirbackgroundknowledgeaboutenergyandpreparesstudentsforthewholeunit.Pre－readingprovidesapictureofagreenhouseandthentellsuswhatagreenhouseisandwhat“greenhousegases”are.Thestudentswillbeledtodiscusswhattheythinkgreenhousegasesdo，leadingtothetopicofthereadingpassage.Readingisapassagefromanenvironmentalmagazineforyoungpeople.Itputsforwardthepossibleeffectofincreasedcarbondioxideintheatmosphereanddifferentpointsofviewaboutit.Italsoanalyzesthecausesoftheearth'sincreasedtemperature.Itposesquestionsandencouragesstudentstothinkabouttheissues.Therearetwographsinitthattellusthe“temperaturedifferencefromlong－termaverage,1860－2000”and“carbondioxidecontentintheatmosphere,1957－1997”．Charactersinthepassage—DrJaniceFoster，GeorgeHambleyandCharlesKeelingareallrealpersonsandtheirviewsreflecttheviewsofsomescientiststoday.Comprehendingconsistsofthreewrittenororalexercisesforthestudentstodosoastohelpthestudentstogetabetterunderstandingofthetext，thatistosay，tohelptheteachertocheckhowmuchthestudentshaveunderstoodthetext.三维目标设计　　　Knowledgeandskills1．Toknowthemeaningsofthefollowingnewwordsandphrases：consume(消费；消耗；耗尽)，comeabout(发生；造成)，random(胡乱的；任意的)，phenomenon(现象)，subscribe(同意；捐赠；订阅；签署文件)，subscribeto(同意；赞成；订购)，fuel(燃料)，quantity(量；数量)，quantitiesof(大量的)，tend(趋向；易于；照顾)，goup(上升；增长；升起)，per(每；每一)，data(资料；数据)，resultin(导致)，trend(趋势；倾向)，catastrophe(大灾难；浩劫)，flood(洪水；洪灾)，oppose(反对；反抗)，opposed(反对的；对立的)，beopposedto(反对)，consequence(结果；后果)，state(陈述；说明)，range(种类；范围)，evenif(即使)，keepon(继续)，glance(看一下；扫视)，steady(平稳的；持续的)，steadily(平稳地，持续地)2．Tolearnaboutsomefactsandviewsaboutglobalwarming.3．Tolearnhowtheinformationisorganized.4．Todevelopthestudents'readingabilitybyskimmingandscanningthepassage.5．Todevelopthestudents'speakingabilitybytalkingaboutglobalwarming.7,Processandmethods1．WhiledoingWarmingUptheteachercanleadinthetopicofthisunitbyshowingstudentssomepicturesorvideosaboutsourcesofenergy，makingthestudentsrecalltheirownknowledgeaboutenergy.2．DuringPre－readingtheteachercangoaroundtheclassroomanddiscussthequestionswithseveralstudents.Thisdiscussionshouldbestudent－centeredandleadthemtothetopicofglobalwarming.Theteachershouldalsoaskthestudentstolookatthegraphsinthereadingpassageandtrytofindoutthegeneralideaofthetext.3．WhiledoingReadingandComprehending，theteachermayfirstaskthestudentstoreadthetextquicklytogetthegeneralideaofeachparagraph.Afterreadingthepassage，studentsareencouragedtoanswersomequestionsanddiscussthetextstructure.4．Toconsolidatethecontentsofthereadingpassage，thestudentsshouldberequiredtoretellthetextintheirownwordsattheendoftheclass.Emotion，attitudeandvalue1．Tomakestudentsrealizetheharmofglobalwarmingandtheimportanceofenvironmentalprotection.2．Todevelopstudents'senseofcooperativelearning.教学重、难点　　　1．Toenablethestudentstolearnaboutglobalwarmingandtodeveloptheirreadingability.2．Toenablethestudentstotalkaboutwhatweshoulddotopreventglobalwarming.Step1　Warmingup1．Warmingupbyreadingandtalking：Readthroughtheexercisewiththeclass.Putstudentsingroupsoffourtotalkaboutwhatweuseenergyfor，whatarethesourcesoftheseenergyandwhetherthesourcesarerenewableornon－renewable.Suggestedanswer：Thesixphotosare：windmills；acoalpowerstation；anoilrefinery；anuclearpowerplant；solarpanels；ahydro－electricdam.2．Warmingupbydiscussion：Drawaformontheblackboardasfollows：ThingsthatuseenergySourcesofenergyRenewable/non－renewable　Letthestudentshaveadiscussionandcollectsuggestionsfromstudentsandwritethemundertheappropriateheading.Suggestedanswer：ThingsthatuseenergySourcesofenergyRenewable/non－renewable7,lightsheatingtelevisioncassetteplayervideorecordercomputerfridgestovehairdryer...coalnon－renewableoilnon－renewablenaturalgasnon－renewablewindpowerrenewablesolarenergyrenewablenuclearenergynon－renewablehydro－electricpowerrenewablebiomassenergyrenewablegeothermalenergyrenewabletidalenergyrenewableStep2　Pre－reading1．Showapictureofagreenhousetostudentsandaskthemwhatagreenhouseismadeofandwhatitspurposeis.Suggestedanswer：It'smadeofglassandplantscangrowinitwhenit'scoldoutside.Askthestudentshowitworks.Suggestedanswer：Theglasstrapstheheatfromthesun，makingtheairwarmsothatplantsgrowbetter.2．Askstudentswhattheythink“greenhousegases”areandwhattheythinkgreenhousegasesdo.Lookatthepictureaboveandexplainittotheirpartners.Suggestedanswer：Greenhousegasesperformthesamefunctionastheglassinaglasshouse：theytraptheheatofthesunandkeeptheairsurroundingtheearthwarm.Thisiscalledthegreenhouseeffect.)Step3　Readingandcomprehending1．FastreadingAskstudentstoreadthepassagequicklysoastogetthekeywordsandgeneralideaofeachparagraphandanswerthefollowingquestions：(1)Whatisthemaintopicofthearticle?________________________________________________________________________(2)Whowrotethemagazinearticle？Whatisthenameofthemagazine?________________________________________________________________________(3)Whatarethenamesofthethreescientistsmentionedinthearticle？Dotheyagreewithoneanother?________________________________________________________________________Suggestedanswers：(1)Globalwarming/thewarmingoftheearth.(2)SophieArmstrong，EarthCare.(3)DrJaniceFoster，CharlesKeeling，GeorgeHambley.Theydon'tagreewitheachother.2．Detailedreading(1)Readthepassagecarefullyandjudgewhetherthestatementsaretrue(T)orfalse(F)．①JaniceFosterbelievesthatglobalwarmingiscausedbytheburningfossilfuels.(　)②Naturalgasisagreenhousegas.(　)③Carbondioxideisabyproductofburningfossilfuels.(　)7,④PeopleacceptCharlesKeeling'sdatabecausehetookaccuratemeasurements.(　)⑤Floodingcouldbeoneoftheeffectsoffutureglobalwarming.(　)⑥GeorgeHambleybelievesscientistsarejustguessingabouttheeffectsofglobalwarming.(　)⑦GeorgeHambleyisworriedabouttheeffectsofcarbondioxideonplantgrowth.(　)⑧Itisclearwhattheeffectsofglobalwarmingwillbe.(　)(Suggestedanswers：TFTTTTFF)3．StructureanalyzingAskstudentstoreadthetextcarefullyandtrytofindouthowmanypartstheycandividethetextintoandfindoutthemainideaofeachpart.PartMainideaPart1(Paragraph______)Part2(Paragraphs______to______)Part3(Paragraphs______to______)Part4(Paragraph______)　　Suggestedanswer：PartMainideaPart1(Paragraph1)Tointroduceadebateovertheissueofglobalwarming.Part2(Paragraphs2to5)Toillustratehowglobalwarmingcomesabout.Part3(Paragraph6)Tolisttwodifferentattitudesamongscientiststowardsglobalwarming.Part4(Paragraph7)It'suptoreaderstothinkanddecidewhetherpeopleshoulddosomethingaboutglobalwarmingornot.Step4　LanguagestudyDealingwithanylanguageproblemifany(wordsorsentencesstudentsmightnotunderstand)tohelpthestudentstohaveabetterunderstandingofthetext.Step5　Listening，readingaloudandunderliningAskstudentstoreadthepassagealoudtothetapeandletthempayattentiontothepronunciationofeachwordandthepauseswithineachsentence.Tellthemtopickoutalltheusefulexpressionsorcollocationsfromthepassagewhilereadingandcopythemtothenotebookafterclassashomework.Collocations：comeabout，Thereisnodoubtthat...，subscribeto，dueto，greenhouseeffect，quantitiesof，tendto，betrappedin，goup，resultin，ontheonehand...ontheotherhand，beopposedto，buildup，keepon.Step6　RetellingAskstudentstotalkaboutglobalwarmingintheirownwords.Givethemsomekeywordsandexpressionsontheblackboard.Thenletthemtrytoretellthepassage.Step7　Homework1．Learntheusefulnewwordsandexpressionsinthispartbyheart.2．TrytofindsomedataaboutglobalwarmingontheInternet，andshowyourclassinthenextperiodandtalkaboutthem.Step8　Reflectionafterteaching________________________________________________________________________7,________________________________________________________________________AboutGlobalWarming(关于全球变暖)GlobalwarmingistheincreaseintheaveragetemperatureofEarth'snear－surfaceairandoceanssincethemid－20thcenturyanditsprojectedcontinuation.Globalsurfacetemperatureincreased0.74±0.18℃(1.33±0.32)betweenthestartandtheendofthe20thcentury.TheIntergovernmentalPanelonClimateChange(IPCC)concludesthatmostoftheobservedtemperatureincreasesincethemiddleofthe20thcenturywasverylikelycausedbyincreasingconcentrationsofgreenhousegasesresultingfromhumanactivitysuchasfossilfuelburninganddeforestation.TheIPCCalsoconcludesthatvariationsinnaturalphenomenasuchassolarradiationandvolcaniceruptionshadasmallcoolingeffectafter1950.Thesebasicconclusionshavebeenendorsedbymorethan40scientificsocietiesandacademiesofscience，includingallofthenationalacademiesofscienceofthemajorindustrializedcountries.ClimatemodelprojectionssummarizedinthelatestIPCCreportindicatethattheglobalsurfacetemperatureislikelytoriseafurther1.1to6.4℃(2.0to11.5)duringthe21stcentury.Theuncertaintyinthisestimatearisesfromtheuseofmodelswithdifferingsensitivitytogreenhousegasconcentrationsandtheuseofdifferingestimatesoffuturegreenhousegasemissions.Moststudiesfocusontheperioduptotheyear2100.However，warmingisexpectedtocontinuebeyond2100evenifemissionsstop，becauseofthelargeheatcapacityoftheoceansandthelonglifetimeofcarbondioxideintheatmosphere.Anincreaseinglobaltemperaturewillcausesealevelstoriseandwillchangetheamountandpatternofprecipitation，probablyincludingexpansionofsubtropicaldeserts.WarmingisexpectedtobestrongestintheArcticandwouldbeassociatedwithcontinuingretreatofglaciers，permafrostandseaice.Otherlikelyeffectsincludechangesinthefrequencyandintensityofextremeweatherevents，speciesextinctions，andchangesinagriculturalyields.Warmingandrelatedchangeswillvaryfromregiontoregionaroundtheglobe，thoughthenatureoftheseregionalvariationsisuncertain.Politicalandpublicdebatecontinuesregardingglobalwarming，andwhatactions(ifany)totakeinresponse.Theavailableoptionsaremitigationtoreducefurtheremissions；adaptationtoreducethedamagecausedbywarming；and，morespeculatively，geoengineering(地球工程)toreverseglobalwarming.MostnationalgovernmentshavesignedandratifiedtheKyotoProtocolaimedatreducinggreenhousegasemissions.7