安徽省滁州市第二中学高中英语Unit22EnvironmentalProtectionTheTwelfthPeriodBulletinBoard&UnitDiary教案北师大版选修8Teachinggoals教学目标Exchangetheinformationoftheworstdisastersinhistory.FinishUnitDiary.1.Abilitygoals能力目标Enablethestudentstowriteaboutwhattheyknowonboard.2.Learningabilitygoals.学能目标Helpthestudentslearnhowtoassesstheirlearningovertheunit.Teachingimportantpoints教学重点HelpstudentstoformgoodhabitsoflearningEnglish.Teachingdifficultpoints教学难点Howtoimprovestudents’learningstrategiesTeachingmethods教学方法Reading,discussingandsummarizingTeachingaids教具准备Multi-computerTeachingprocedures&ways过程与方式StepIRevisionCheckthehomework.Pointoutthecommonerrorsstudentshavemade.StepIIAwarenessAskstudentstoreadthethreedisastersonPage17.Thentheywilldiscussingroups.Eachmemberwillspeakoutwhattheyknowabouttheworstdisasters.Aftertheydiscusswhattheworstdisastersinhistoryareingroups,eachofthemwillwritewhatheorsheknowsonboard.Thewholeclasswillexchangetheirinformation.IfstudentshaveanaccesstotheInternet,theymayfindwhattheyneedeasily.Iftheydon’t,Teachermayprovidesome.Tangshan:TheDeadliestEarthquakeAt3:42a.m.onJuly28,1976,amagnitude7.8earthquakehitthesleepingcityofTangshan,innortheasternChina.Theverylargeearthquake,strikinganareawhereitwastotallyunexpected,obliteratedthecityofTangshanandkilledover240,000people—makingitthedeadliestearthquakeofthetwentiethcentury.Whatwasthebiggestearthquakeever?Thebiggestearthquakeknowninhistoricaltimesoccurredon22May1960inChile,withamagnitudeMwof9.5.ItoccurredbecauseofaruptureintheEarth'scrustthatextendedhorizontallyabout1000kmalongthecoastofSouthAmerica;insomeplacesthisquakecausedverticalupliftsaslargeassixmeters.Thesecondbiggestearthquakeknown,withamagnitudeof9.2,occurredinAlaskaon27March1964;ithadarupturelengthof800km,andcausedasmuchas11metersofuplift.TheoreticalcalculationssuggestthattheseearthquakesarejustaboutaslargeaspossibleforplanetEarth.Supposeahypotheticalearthquakerupturestheentire100kmthicknessoftherigidtectonicplates,andsupposethisruptureextendsalongafaultwithlength1000kmwithanaverageslipof10meters.Calculationsshowthatthishypotheticalearthquakewouldhaveamagnitudeofabout9.3.Largerearthquakeswouldhavetoruptureanevenlongerfaultwithanevengreateraverageslip;apparentlythisjustdoesn'thappen.Whatwasthemostdeadlyearthquakeever?The27July1976earthquakeinTangshan,China(MS=7.9)causedthegreatestnumberofdeathsofanyrecentquakeknown;themostreliableestimatesarethatabout242,000liveswerelost.Tangshanhadapre-quakepopulationofaboutamillionpeople;themainindustryismining.OnereasonthedeathtollwassohighisbecausemostofthestructuresinTangshanweremultiple-story,unreinforcedbrickandconcretebuildings.Estimatesoflossoflifefromtheworstearthquakedisastersareveryunreliable;understandably,whentensofthousandsofpeoplearedeadandmostbuildingsareinruins,therearemoreimportantthingstodothantocountbodies.However,therehavebeenaboutfivequakesinthetwentiethcenturywherereportsofliveslostexceeded100,000.MostexpertsacceptthatthemostdeadlyearthquakeinhistoricaltimesoccurredinShanxiProvince,Chinain1556;about830,000liveswerelost.StepIIIUnitDiaryGetstudentstoassesstheirlearningovertheunit.BycompletingUnitDiarystudentswilllearnwhattheirdifficultyisandwhattheyshoulddotoimprove.StepIVHomeworkPostyourviewonhowtoEnglishwellontheBulletinBoard.附件I.本单元课文注释与疑难解析1.Inthel...