Unit13TheWaterPlanetWarmingupAbluewater-coveredballOurplanetAblueball•世界地图thePacificOceantheAtlanticOceantheArcticOceantheIndianOcean•世界地图AsiaEuropeNorthAmericaSouthAmericaAntarcticaOceaniaAfricaWhatpropertiesorcharacteristicsWhatpropertiesorcharacteristicsdoyouknowaboutwater?doyouknowaboutwater?colorlesstastelessodorlessthreeformsfeelingwetdissolvingabsorbingheatPropertiesProperties…CollectasmanywordsaspossibleCollectasmanywordsaspossiblerelatedtowater.relatedtowater.steamiceoceanlakeriverrainsweatfishwatewaterr…Donotletyourtearbethelastdropofwaterintheworld!Let’sdosomeexperimentstoknowLet’sdosomeexperimentstoknowsomeofthepropertiesofwater.someofthepropertiesofwater.WhatWhatpropertyofwaterpropertyofwaterdoedoeseachofthefourexperimseachofthefourexperimentsillustrate?entsillustrate?ThepieceofpaperThepieceofpaperwillclingtothecupwillclingtothecupBecauseoftheBecauseoftheairpressure.airpressure.A.Oilfloatsonthewater.A.Oilfloatsonthewater.B.Waterfloatsontheoil.B.Waterfloatsontheoil.C.Theymixtogether.C.Theymixtogether.BecauseofthedifferentBecauseofthedifferentdensityofthetwo.densityofthetwo.Whatwillhappen?(Whataboutwatermixedwithmilk?)ThechalkwillbedissolvedThechalkwillbedissolvedBecausethewatermoleBecausethewatermoleculeispolar,itcanbreakculeispolar,itcanbreakdownbothsolidsandgasdownbothsolidsandgases.es.TheicecubeputintheglaTheicecubeputintheglasswithfreshwaterwillfloatsswithfreshwaterwillfloatinthewater,whiletheoneiinthewater,whiletheoneinsaltwaterwillfloatonthnsaltwaterwillfloatonthewaterewaterBecauseofthedifferentBecauseofthedifferentdensityofthewaterdensityofthewaterExperiment1showshowairpressurecausesapieceofcardboardtoclingtoanupturnedglassofwater.Experiment2showshowsubstancewithdifferentdensitybehavewhenplacedinthesamecontainer.Picture1Picture2Experiment3isanexampleofhowwaterdissolvessubstanceandobjectsExperiment4illustratessomeofthedifferencesbetweensaltwaterandfreshwater.Picture3Picture4Waterisamusttolife.Waterisamusttolife.Withoutwater,Withoutwater,lifewouldnotexist.lifewouldnotexist.2222ndnd,March,MarchWorldWaterDayWorldWaterDay20052005willbeguidedbythewillbeguidedbytheupcomingwaterdecade'sthemeupcomingwaterdecade'stheme""WaterforLifeWaterforLife".".ItwillbethestartingdayforthisInternationalItwillbethestartingdayforthisInternationalDecadeforAction,"WaterforLife"2005–2015.DecadeforAction,"WaterforLife"2005–2015.ThethemeforWorldThethemeforWorldWaterDayWaterDay20042004waswas““WaterandDisasterWaterandDisaster”.”.WaterisWaterisbeingusedfor…beingusedfor…WaterisWaterisbeingusedfor…beingusedfor…ElectricityElectricityAgricultureAgricultureHomeuseHomeuseIndustryIndustryTransportTransportEntertainmentEntertainmentTakeTakehomeusehomeuseforforexampleexample,,(YoucanalsorefertoEx.1,Grammar,P.98)(YoucanalsorefertoEx.1,Grammar,P.98)Howiswaterbeingused?Howiswaterbeingused?WhatpropertyofwaterenablesittobeusedinthisWhatpropertyofwaterenablesittobeusedinthisway?way?Whydoweusewaterinthisway?Whydoweusewaterinthisway?Whobenefitsfromusingwaterinthisway?Whobenefitsfromusingwaterinthisway?Isthisagoodwaytousewater?Isthisagoodwaytousewater?WhataresomedisadvantagesofusingwaterinthisWhataresomedisadvantagesofusingwaterinthisway?way?DiscussthesixpictureswiththeDiscussthesixpictureswiththefollowingquestionsforyourfollowingquestionsforyourreference.Don’tforgettomakereference.Don’tforgettomakenotes.notes.Thewaterisbeingusedto/for…Thewaterisbeingusedto/for…Weshould/could…Weshould/could…Whatwillwedoif…?Whatwillwedoif…?Ifwe…,wecan…Ifwe…,wecan…Itwouldbebetterto…Itwouldbebetterto…Canyouthinkofabetterway?Canyouthinkofabetterway?MakeadialogueonthebasisoftheMakeadialogueonthebasisoftheresultsofyourdiscussion,usingtheresultsofyourdiscussion,usingthefollowingusefulexpressions.followingusefulexpressions.ConserveWaterConserveWaterItbringsgrowthandItbringsgrowthandlifelifetolivingorganismstolivingorganismsAworldwithoutwaterAworldwithoutwaterisdeadisdeadSAVEWATERSAVEWATERtotoremainremainaliveandhealthy.aliveandhealthy.
