高一英语 Unit19《Modern agriculture第一课时》精品教案 旧人教版第一册文档格式.docx

高一英语 Unit19《Modern agriculture第一课时》精品教案 旧人教版第一册文档格式.docx

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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.HeattendedamunitycollegeinIowafortwoyearstostudydieselmechanics.Thenheopenedthisrepairshopforfarmmachinery.Kendallalsoplantsandharvestsover30000bushelsofcorneachyear,butitistheinefromtherepairshopthathasenabledhimtostaywithinthefarmingmunity.Theheavyequipmentusedonthefarmstodayisinconstantneedofmaintenance,andrequiresprecisiontoolingforrepairs.Byfar,themostimpressiveandcertainlythemostcostlypieceoffarmequipmentusedonasmallfarmisaharvestingmachinecalledabine,whichcancostupto$100000.

ThistypeofmachineryiswhatmakestheAmericanfarmsoefficient.Withabine,onemanandhisfamilycanharvestanentirecropofa500acrefarmintwoweeks.Thevalueofthebineisthatitperformsseveralfunctions.Asitmovesthroughafieldofcorn,thissophisticatedmachinecutsthestalk,pluckstheear,discardsthestalk,shucksthecornkernelsofftheearanddepositesthekernelsinastoragebinintheback.Then,aspinningdeviceintherearofthebineshredsthehusksandshaftsandscattersthemacrossthefield,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'

2.Discussiontoletthestudentsexpressthemselvesfreely.

3.Groupworkorpairworktogiveeverystudentachancetoexpressthemselves.

TeachingAids:

1.ataperecorder

2.aprojectorandsomeslides

3.aputer

TeachingProcedures:

stepⅠ.GreetingsandRevision

T:

Goodmorning,everyone.

Ss:

Goodmorning,teacher.

Sitdown,please.Inthisclass,I'

llcheckyourhomeworkfirst,WangPing,readyourhomeworktous,…

（Theteacherchecksthestudents'

homeworkandhaveadiscussionwiththestudentsaboutthemistakeWangPingmade.Letthestudentshaveaclearunderstandingandcorrectit.）

stepⅡ.Preparationforlisteningandspeaking

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

PleaseturntoPage32.Let'

sdoWarmingup.（TeachershowsthegraphsonPage32onthescreen.）LookatthetwographsanddiscussthequestionsonPage32.Youcandoitinpairsorgroups.Inafewminutes,I'

llasksomestudentstotalkaboutthem.（Studentsbegintodiscussthequestions.Andteachergoesandjoinsthem.Afewminuteslater,teachersaysthefollowing.）

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.

Whydoyouthinkthishappens,SB?

SB:

ItisallbecauseoftheParty'

sgoodpolicies.

Verygood.Itistrueandeveryonecanseethat.Howhasagriculturalproducechangedduringthefirsthalfofthe1990s?

Andwhatdoyouthinkcausedthesechanges?

SC:

Fromthefirsthalfofthe1990s,scientistsstartedtodevelopnewtechniquestoincreaseagriculturalproductionwithoutcausingdamagetotheenvironment.Especiallythenewtechnique,“GM”,hasmadeagriculturalproductionincreasecontinuously.Scientistsdevelopnewkindsofseeds,bettercows,pigs,sheepaswellasfish.Itisthenewtechniquesthatmakeallthispossible.

Doyouagreewithhim,SD?

SD:

Yes,Ido.AndIwanttogiveananswertothethreequestion.

Good,pleasesaythat.

Withthechangesinpeople'

seatinghabits,agricultureaswellasnaturewillhavetochange,too.Peopleareeatingmoremeatandmilk.Thatistosay,theyneedmorefish,pigs,sheepandcattleaswellaspoultry.Tofeedtheseanimals,weneedmoregrain,especiallymoregrass.Toprotectourenvironment,thewaystoraiseanimalshavechanged.Withthedevelopmentofmodernscienceandtechniques,someofthefieldsarenotneededtoproducemorefood.Wecangrowgrass,flowersetc.onthem.Lessfarmersareneededandtheycandootherkindsofwork.

StepⅣ.Listening

Somuchforthediscussion.Nextwe'

lldolistening.Thepassageyou'

lllistentoisaboutfarming.Ittellsusaboutfarmingofallcountriesinearlytimesandprotectionofnatureandenvironment.Listentothetapecarefullyanddotheexercisesconcerned.Now,readtherequirements,please.（Studentsreadtherequirements.）Nowdoyouknowwhatyou'

llhavetodoafterlisteningtothepassage?

（Ss:

Yes.）Duringlistening,I'

llplaythetapethreetimes.Afterlisteningforthefirsttime,youcanleaveovertheonesyouarenotsureabout.YoucandothemwhenIplaythetapeforthesecondorthethirdtime.Checkyouranswerswithyourpartnerafterlistening.Areyouclear?

Yes.）（Atlast,teachershowstheanswersonthescreen.）

StepⅤ.Speaking

Nowlet'

sdospeaking.Thispartsaysthatagroupoffarmersinyourareahavebeengivenalargepieceofland.Thevillagerstogetherwiththevillageleaderhavetodecidehowtousetheland.Workingroupsoffivestudents.Eachgroupmemberwillplayoneoftheroles.Preparerolecards,discusstheproblemandtrytomakeadecision.Beforediscussion,whocangiveussomeusefulexpre