人教版高中英语Unit19 Modern agriculture教案.docx
《人教版高中英语Unit19 Modern agriculture教案.docx》由会员分享,可在线阅读,更多相关《人教版高中英语Unit19 Modern agriculture教案.docx(47页珍藏版)》请在冰豆网上搜索。
人教版高中英语Unit19Modernagriculture教案
Unit19 Modernagriculture
Ⅰ.TeachingGoals:
1.Talkaboutmodernagricultureandtheeffectsithasonpeople'slife.
2.Practisegivingadviceandmakingdecisions.
3.Use“It”foremphasis.
4.Readstatisticalgraphs.
5.Writeaplanforavegetablegarden.
Ⅱ.TeachingTime:
Fiveperiods
Ⅲ.BackgroundInformation:
1.AnAmericanSmallFarm
Lastyear,atharvesttime,wevisitedtheSteenhoekfarm,whichis2200mu,or340acres.Typicalfamilyfarmsarerunentirelybyfamilymembers,witheverymemberplayingavitalpartintheoperation.BothofthesefamiliesaredescendantsofDutchimmigrantswhosettledhereoveracenturyago.
TheSteenhoekfarmsupports3generations.ThefamilyofMr.andMrs.Steenhoekincludesthreechildrenand2grandchildren.Aswewillsee,thisfamilyisanexcellentexampleofhardworking,experiencedfarmerswhostayonthelandnotpurelybecauseofprofit,butbecausetheyarelivingalife-stylethatsatisfiesthem.SixtypercentoftheSteenhoek'sacresaredevotedtopastureland,onwhichtheyraise120beefcattle.Therestofthelandisusedforgrowingcorn.
Fifteenyearsago,theAmericanfarmeconomywasbooming.Farmerscouldspecialize,raisingonecrop,oronetypeofanimal.Today,withanuncertainfarmeconomy,suchanideaisconsideredfoolhardy,anddiversifyingisonewaythatfarmerscanlessontheirriskofloss.Forexample,ifweatheraffectsthesizeofacrop,thesaleofthelivestockwillmakeupthedifference.Iftheanimalsareplaguedbydisease,atleastthereisgraintotaketomarket.
KendallSteenhoek,Simon'seldestson,divideshistimebetweenrunningthismachineshopandfarmingzooacresofcorn.HeattendedacommunitycollegeinIowafortwoyearstostudydieselmechanics.Thenheopenedthisrepairshopforfarmmachinery.Kendallalsoplantsandharvestsover30000bushelsofcorneachyear,butitistheincomefromtherepairshopthathasenabledhimtostaywithinthefarmingcommunity.Theheavyequipmentusedonthefarmstodayisinconstantneedofmaintenance,andrequiresprecisiontoolingforrepairs.Byfar,themostimpressiveandcertainlythemostcostlypieceoffarmequipmentusedonasmallfarmisaharvestingmachinecalledacombine,whichcancostupto$100000.
ThistypeofmachineryiswhatmakestheAmericanfarmsoefficient.Withacombine,onemanandhisfamilycanharvestanentirecropofa500acrefarmintwoweeks.Thevalueofthecombineisthatitperformsseveralfunctions.Asitmovesthroughafieldofcorn,thissophisticatedmachinecutsthestalk,pluckstheear,discardsthestalk,shucksthecornkernelsofftheearanddepositesthekernelsinastoragebinintheback.Then,aspinningdeviceintherearofthecombineshredsthehusksandshaftsandscattersthemacrossthefield,toserveasmulch,cuttingdownonthepossibilityofsoilerosionfromwinterrains.ThemachineisevenmoreamazingwhenyouthinkthatithasbeeninuseonAmericanfarmsforonlyonegeneration.
2.Genes
Everylivingcellcontainsgenes.Theyaretoosmalltobeseeninamicroscope,buttheyarevitallyimportant.Eachsetofgenesinthebodycontainsalltheinstructionsneededtomakeahumanbeing.Somegenesdeterminehaircolor.Somedeterminetheshapeofanose.Somegeneshelpdetermineyourheightandevenyourweight.
GenesaremadeofachemicalcalledDNA—thelettersstandfordeoxyribonucleicacid(脱氧核糖核酸).Intheearly1950's,twoscientists,FrancisCrickandJamesWatson,figuredouthowthepartsofDNAfittogether.Oncescientistsunderstoodthisstructure,itbecamepossibletotakepiecesofDNAapartandputthemtogetherinnewways.Newkindsofgenescouldbemadeinthismanner.
Scientistshavestudiedthegenesofmanyplantsandanimals.Theyhaveworkedoutwhichgenesaffectthecolorofatomatoandthesticknessofitsskin.Workingoutwhichgenesdeterminewhichfeaturesiscalledgeneticmapping,scientistshavebeguntheHumanGenomeProject,anambitiousefforttomapallthegenesinthehumanbody.
Somegenesmaybeeffective.Forexample,somethingmightbewrongwiththegenethatmakesbloodclot(凝聚).Anindividualbornwiththisdefectivegenecouldsufferserioushemorrhages(出血)orevenbleedtodeathbecausehisorherbloodfailstoclot.Ifscientistseverlearnhowtomapallthegenesinourbodies,theycoulddeterminewhetherornotanunbornchildhasanydefectivegenes.Theymightevendiscoverhowtotreatthesegenesbeforethechildisborn.
TheFirstPeriod
TeachingAims:
1.Improvethestudents'speakingabilitybypractisinggivingadviceandmakingdecisions.
2.Enablethestudentstomastertheexpressionsofgivingadviceandmakingdecisions.
3.Getthestudentstolearnmoreaboutagriculture.
TeachingImportantPoints:
1.Howtoexpressoneself,usingwhatislearnedorgiven.
2.Howtoadvisesb.todosomethingandhowtomakedecisions.
TeachingDifficultPoints:
1.Theusageofsomeexpressions.
2.Howtoimprovethestudents'listeningability.
TeachingMethods:
1.Listeningsomematerialstoimprovethestudents'listeningability.
2.Discussiontoletthestudentsexpressthemselvesfreely.
3.Groupworkorpairworktogiveeverystudentachancetoexpressthemselves.
TeachingAids:
1.ataperecorder
2.aprojectorandsomeslides
3.acomputer
TeachingProcedures:
stepⅠ.GreetingsandRevision
T:
Goodmorning,everyone.
Ss:
Goodmorning,teacher.
T:
Sitdown,please.Inthisclass,I'llcheckyourhomeworkfirst,WangPing,readyourhomeworktous,…
(Theteacherchecksthestudents'homeworkandhaveadiscussionwiththestudentsaboutthemistakeWangPingmade.Letthestudentshaveaclearunderstandingandcorrectit.)
stepⅡ.Preparationforlisteningandspeaking
T:
Today,we'regoingtolearnanewunit,Unit19,ModernAgriculture(Teacherwritesthefollowingontheblackboard:
Unit19Modernagriculture,theFirstPeriod).First,let'slearnthenewwordsofthisperiod.Lookatthescreen:
Newwords:
producen.产量、产物、农产品
effectn.结果、影响、作用
diken.堤坝;排水沟
droughtn.干旱
leadern.领导者
leadv.领导、带领
canen.细长的茎、藤条
sugar-canen.甘蔗
tobaccon.(烟草)制品;抽烟
localadj.地方的、当地的
(Teacherasksonestudenttoreadthenewwords,thencorrectsthemistakesthestudentmade.)
StepⅢ.Warmingup
T:
PleaseturntoPage32.Let'sdoWarmingup.(TeachershowsthegraphsonPage32onthescreen.)LookatthetwographsanddiscussthequestionsonPage32.Youcandoitinpairsorgroups.Inafewminutes,I'llasksomestudentstotalkaboutthem.(Studentsbegintodiscussthequestions.Andteachergoesandjoinsthem.Afewminuteslater,teachersaysthefollowing.)
T:
Areyouready?
Whocangiveusatalkaboutthefirsttopic?
SA,howarepeople'seatinghabbitschangingovertheyears?
SA:
Fromthefirstgraph,wecanseethattheeatinghabitsofthepeopleinourcountryhavechangedgreatly.Before1949,theyhadnotenoughtoeatandoftenwenthungry.Oncenaturaldisastershappened,agreatnumberofpeoplewoulddieofhunger.Beforethereformingandopeningtotheworld,grainwasstillabigproblem.Peoplemainlylivedoncornandfewkindsofvegetables.Sincethe1980s,especiallythe1990s,people'seatinghabitshavegreatlyimproved.Peoplecaneatwhatevertheywant.Moreandmorepeopleeatlessgrain,moremeatandeggsandsoon.Moreandmorepeopleturntheireyestomeat,eggs,milkandallkindsofgreenvegetables.
T:
Whydoyouthinkthishappens,SB?
SB:
ItisallbecauseoftheParty'sgoodpolicies.
T:
Verygood.Itistrueandeveryonecanseethat.Howhasagriculturalproducechangedduringthefirsthalfofthe1990s?
Andwhatdoyouthinkcausedthesechanges?
SC:
Fromthefirsthalfofthe1990s,scientistsstartedtodevelopnewtechniquestoincreaseagriculturalproductionwithoutcausingdamagetotheenvironment.Especiallythenewtechnique,“GM”,hasmadeagriculturalproductionincreasecontinuously.Scientistsdevelopnewkindsofseeds,bettercows,pigs,sheepaswellasfish.Itisthenewtechniquesthatmakeallthispossible.
T:
Doyouagreewithhim,SD?
SD:
Yes,Ido.AndIwanttogiveananswertothethreequestion.
T:
Good,pleasesaythat.
SD:
Withthechangesinpeople'seatinghabits,agricultureaswellasnaturewillhavetochange,too.Peopleareeatingmoremeatandmilk.Thatistosay,theyneedmorefish,pigs,sheepandcattleaswellaspoultry.Tofeedtheseanimals,weneedmoregrain,especiallymoregrass.Toprotectourenvironment,thewaystoraiseanimalshavechanged.Withthedevelopmentofmodernscienceandtechniques,someofthefieldsarenotneededtoproducemorefood.Wecangrowgrass,flowersetc.onthem.Lessfarmersareneededandtheycandootherkindsofwork.
StepⅣ.Listening
T:
Somuchforthediscussion.Nextwe'lldolistening.Thepassageyou'lllistentoisaboutfarming.Ittellsusaboutfarmingofallcountriesinearlytimesandprotectionofnatureandenvironment.Listentothetapecarefullyanddotheexercisesconcerned.Now,readtherequirements,please.(Studentsreadtherequirements.)Nowdoyouknowwhatyou'llhavetodoafterlisteningtothepassage?
(Ss:
Yes.)Duringlistening,I'llplaythetapethreetimes.Afterlisteningforthefirsttime,youcanleaveovertheonesyouarenotsureabout.YoucandothemwhenIplaythetapeforthesecondorthethirdtime.Checkyouranswerswithyourpartnerafterlistening.Areyouclear?
(Ss:
Yes.)(Atlast,teachershowstheanswersonthescreen.)
StepⅤ.Speaking
T:
Nowlet'sdospeaking.Thispartsaysthatagroupoffarmersinyourareahavebeengivenalargepieceofland.Thevillagerstogetherwiththevillageleaderhavetodecidehowtousetheland.Workingroupsoffivestudents.Eachgroupmemberwillplayoneoftheroles.Preparerolecards,discusstheproblemandtrytomakeadecision.Beforediscussion,whocangiveussomeusefulexpressionsaboutgiving