unit13.docx

unit13.docx

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unit13

Unit13Thewaterplanet

Ⅰ.BriefStatementsBasedontheUnit

Asweallknow,theearthisanoceanplanetand99%percentofthelivingspaceonearthisintheoceans.Itiswaterthatmakestheoceansuchagreatplacetolivein.Thisunitmainlydealswiththepropertiesofwaterandhowthepropertiesofwatermaketheoceanbecomesoimportant.Welearnthisunittohelpstudentsnotonlyknowaboutthepropertiesofwater,butalsolearnhowtousewaterinagoodway.Besides,welearnthisunittoletstudentsrealizetheimportanceofprotectingwater.Ofcourse,itisnecessaryforstudentstomastertheimportantphrasesandsentencesintheunit.MeanwhileweshouldreviewsomeimportantusageofModalVerbs.

Ⅱ.TeachingGoals

1.Talkaboutwaterandtheocean.

2.Practisecommunicativeskills.

3.ReviewModalVerbs.

4.Writeanexplanationparagraph.

Ⅲ.BackgroundInformation

1.WhatLiesundertheBlueWater?

Justlikethehouseswelivein,theoceanhasseveral“floors”orlayers.Differentfishliveondifferentlayersandareneighbours,thoughnotalwaysfriendlyones!

Theocean’stoplayeristhesunlitzone（透光层）.Itgoesdowntoaround200metersbelowwater.Thislayeriswarmandbright.Itisalsohometomostplantsandfish.Manyfishinthislayerarestreamlined,sotheycanquicklyswimfromdangerandcatchfood.

Thetwilightzone（弱光层）isthenextlayerandisfromabout200to600metersbelowwater.Almostnoplantsgrowhere.

Manyanimalsinthiszoneswimuptothesurfaceatnighttofeed,andmoveintodeeperwatersduringtheday.Theyalsoeateachother,somanyofthemhavesharpteethandverybigmouths.

Manyfishinthiszonedon’thaveastreamlinedbodybecausetheylieandwaitforpreytocometothem.

Belowthetwilightlayeristhemidnightzone（无光层）.Itisfrom600meterstothebottomofthesea.

Thewateriscoldandcompletelydark.Noplantsliveherebutmanysmallanimalscan.

Manyanimalsinthetwilightandmidnightzonesproducetheirownlights.Theangler-fish（琵琶鱼）isoneofthem.Ithasabeautifullightonitsheadtoattractprey!

MaybeyouhaveseenoneofthecoolestfilmsFindingNemo（《海底总动员》）.DoyourememberMarlin,Nemo’sfather,“borrowed”lighttohelpDoryread?

Thatwasn’taflashlight,itwasafish!

Theyalsouselighttofrightenenemiesandto“talk”witheachother.

2.Water

Afamilyofsixneedsover20gallonsofwateraday,justforbasicdrinking,cookingandkeepingclean;butonlyoneinthreeoftheworld’shouseholdshasawatersupplyinthehome.

Mostothersgettheirwaterfromrivers,lakesspringsorholesintheground,or,intown,fromstand-pipessharedwithhundredsofotherfamilies.

Throughouttheworld’spoorestcountrieswomendamagetheirhealthandlosehoursofeverydaycarryinghugecontainersofwater—upto44lbsinweight—oftenfromsourcesseveralmilesaway.

Alltoofrequentlytheybringhomesicknessordeath,aswellaswater.Untreatedwater,whichmayhavecomefromamuddyholesharedwithcattle,canbelethal,especiallyforyoungchildren.Tosinkawellorpipewaterfromanaturalspring,andmaintainthesystemafterwards,peopleneedaccesstolandwithawatersource,tocapital,equipmentandtechnicalknow-how.Intownstheymayneedtolobbythelocalwaterauthoritytorepairorextendexistingsystems.

Waterisprecious,andaccesstoitgivespower—tolandownerswithwellsontheirland,ortocountrycontrollingmajorinternationalrivers.Thedemandsontheearth’swaterresourcesaregrowingrapidly,partlyasaresultofpopulationgrowth,butevenmorebecauseindustrynowusessuchhugequantities—ittakes100000gallonstoproduceacar.

Ⅳ.TeachingTime:

Fiveperiods

TheFirstPeriod

TeachingAims:

1.Learnandmasterthenewwordsandtheusefulexpressionsofthispart.

Words:

cube,sailor,disadvantages,entertainment

Phrases:

comeupwith,happento

Usefulexpressions:

Thewaterisbeingusedto/for…

Weshould/could…

Ifwe…wecan…

Itwouldbebetter…

2.Learnsomethingaboutwaterbydoingexperiment.

3.Dosomelistening.

4.Improvethestudents’speakingabilitybytalking.

TeachingImportantPoints:

1.Makethestudentsbefreetotalkaboutwater.

2.Improvethestudents’listeningabilitybylistening.

TeachingDifficultPoints:

1.Howtofinishthetaskofspeaking.

2.Howtoimprovethestudents’listeningability.

TeachingMethods:

1.Listening-and-answeringactivitytohelpthestudentsgothroughwiththelisteningmaterial.

2.Individual,pairorgroupworktomakeeverystudentworkinclass.

TeachingAids:

1.themultimedia

2.theblackboard

3.anemptyglass,abottleofwaterandabottleofvegetableoil

TeachingProcedures:

☞StepⅠGreetingsandLead-in

T:

Hello,everyone.

Ss:

Hello,teacher.

T:

Attention,please.Asweallknow,everyyearduringtheSpringFestivalandLanternFestivalinourcountry,peopleliketoseetheliondanceandguesstheriddles.Doyouliketoguesstheriddle,then?

Ss:

Yes.

T:

OK.NowIhaveariddle.Pleaseguessit.

（Teacherusesthemultimediatoshowtheriddleonthescreen.）

It’sveryimportanttoalltheanimalsandplants.

It’salsoimportanttohumanbeings.

It’sliquidatroomtemperature.

Everydayyoukeepintouchwithit.

Youcan’tlivewithoutit.

（athing）

T:

What’sit?

Ss:

It’sveryeasy.It’swater.

T:

Yeah,todaywewilltalkaboutwater.Nowpleasetellmewhatyouknowaboutwater.

S1:

Waterisusedtodrink.

S2:

Watercanbeusedtowatertheflowers.

S3:

Ithinkwatercanbeusedtomakeelectricity.

☞StepⅡWarmingup

T:

Thankyouforyourideas.Nextwewillmakesomeinterestingexperiments.Maybeyoucanlearnmoreaboutwaterfromthefollowingexperiments.S4,wouldyouliketocomeheretohelpme?

S4:

I’dloveto.

T:

Now,lookatLiLeiandme.Wewillbegin.Youshouldwatchtheexperimentcarefullyandtrytotellmewhathappensandwhy.

（Teacherputsabottleofwater,abottleofvegetableoilandanemptyglassonthedesk.）

T:

S4,poursomewaterandsomevegetableoilintotheemptyglass.Otherstudents,pleasewatchcarefully.

（Afewsecondslater.）

Ss:

Fantastic!

Theliquidintheglasshasbecometwoparts.

T:

Trytodescribeitindetail.

S5:

Letmetry.Thepartaboveisvegetableoilandthepartbelowiswater.ButIdon’tknowwhy.

T:

Goodquestion.Who’dliketoanswerhisquestion?

（Nobodyanswershisquestion.）

T:

Perhapsitisalittledifficulttoansweritimmediately.Nowyoucanhaveadiscussionaboutthereasonforit,usingwhatyouhavelearntinphysics.

（Teacherletsstudentsdiscussingroupsoffour.Afewminuteslater,teachercheckstheiranswers.）

T:

Whowantstoexplainthephenomenon?

S6:

Ithinkwaterisheavierthanoil,sovegetableoilisonthetopofthewater.

T:

Whohasdifferentideas?

S7:

Ithinkweshouldsaythatthedensityofwaterishigherthanthedensityofvegetableoil,sotheresultformed.

S8:

What’sthemeaningof“density”?

S9:

“Density”is“密度”inChinese.

T:

Doyouagreewiththereasonforit?

Ss:

Yes.Weagreewiththeidea.

T:

Asweknow,ifwepourmilkandwaterintooneglass,wecan’ttellwherewaterisandwheremilkis.Butjustnowwepouredoilandwaterintooneglass,itissodifferentnow.Doyouknowwhy?

Ss:

Becauseoilcan’tdissolveinwater,butmilkcan.

T:

Verygood.Let’smakeasummaryabouttheexperiment.Ifwepourvegetableoilandwaterintooneglass,theliquidwillbecometwopartsbecauseoilcan’tdissolveinwater.Sincethedensityofwaterishigherthanvegetableoil,vegetableoilwillbeontopofthewater.Isthatclear?

Ss:

Yes.

T:

Wouldyouliketowatchanotherexperiment?

Ss:

I’dloveto.

T:

OK.I’llperformthenextexperimentbymyself.Lookatme.Ihaveaglassofwater.NowI’llcoveritwithapieceofthickpaper.Attention,please.

（Teacherputsonehandonthepaperandturnstheglassupsidedown.Thenteacherslowlytakeshis/herhandawayfromthepaper.）

T:

Whatcanyousee?

Ss:

Thepieceofpaperdoesn’tfallandthewaterintheglassdoesn’tflow.

T:

Yes.Youareright.Nowyouaregivenafewminutestohaveadiscussionaboutthereasonforit.

（Teachergivesstudentsafewminutestodiscuss,andthencheckstheiranswers.）

T:

Whocantellusthereasonwhythepieceofpaperdoesn’tfallandthewaterdoesn’tflow?

S10:

Iwanttohaveatry.Whentheglassofwatercoveredwithapieceofpaperisturnedupsidedown,thepressurefromairtothepieceofpaperisbiggerthanthepressurefromthewaterintheglasstothepieceofpaper.Sothepaperwon’tfallandthewaterwon’tflow.

T:

Excellent!

Thankyouforyourexplanation.Iamverygladtoseethatyouareallinterestedinmakingexperiments.Afterclass,youcancarryoutanothertwoexperimentsonPage17.Whenyouperformthem,trytodescribewhathappensandwhy.OK?

Ss:

OK.

T:

Now,let’slookatapicture.

（Teachershowsapictureonthescreen.）

T:

Whatcanyousee?

Ss:

Thereisariverinthepicture,butit’sverydirty.

T:

Anythingelse?

S11:

Therearesomeplasticbagsandemptytinsonthesurfaceoftheriver.

T:

Yes.Weallknowwaterisimportanttohumanbeingsandalltheanimalsandplants.Unfortunatelywaterisbeingpollutednow.Whatdoyouthinkwecandotoprotectthewateronourplanet?

（Teachergivesstudentsenoughtimetoprepare.Whentheyprepare,teachergoesamongthestudentstohelpthemtoexpresstheirideascorrectly.）

Sampleanswer:

Toprotectthewateronourplanet,Ithinkweshouldsaveeverydropofwaterandstopthrowingrubbishintowater.Besides,weshouldtryourbesttohelpthepeoplearoundusrealizetheimportanceofusingandprotectingourwater.

☞StepⅢListening

T:

Next,let’sdosomelistening.TurntoPage18andloo