高二英语课件高二英语下学期unit13reading高二英语课件

Canyougivemesomewords,phrasesorsentencesrelativetowater?Whatpropertiesorcharacteristicsdoyouknowaboutwater?colorlesstastelesshavingnofixedshapethreeformsfeelingwetkeepinglevelabsorbingheatpropertiesFastReading:1.Waterhasarelativelylowfreezingpoint.2.YouwilldrownintheDeadSea.3.Waterisliquidatroomtemperature.4.Saltwaterisheavierthanfreshwater.5.Thedensityofwateris1,000kg/m3.6.Theoceanwillfreezetotally.7.Thesalinityoftheearth’soceansisabout3.5%8.Whenwaterfreezes,itsdensityincreases.Introduction(Para1):Whydowecallitanoceanplanet?Lifeontheearthbeganintheoceansaboutthreebillionyearsago;99%ofthelivingspaceonearthisintheoceans;Thereareaboutfivemillion(known)speciesintheoceans;Lifeintheoceansrangesfromtinyplanktontogiantsharksandwhales.Oceanisagreatplacetolive.---Water.Body(Para2-6)ThePropertiesofWaterChemicalStructureSalinityDensityHeatCapacityOceanMotionHeatCapacity(Para5)HeatCapacitytheamountofenergyittakestoraisethetemperatureofasubstancebyonedegreecentigraderelativelyhighwaterheatabsorbandgiveoffCreateastableenvironmentsotheoceanisasafeandcomfortablehabitat.Salinity(Para3)seawater=saltwaterdissolvedsolidsandgasespurewaterThesalinityoftheoceans:____________________________________.thirty-fivepartsperthousand(3.5%)Keypoints:(onekilogramme)(35grammes)Thesalinityaffects:_______and______________.weightfreezingpoint(heavier)(lower)Density(Para4)DensitymassvolumeRelationshipKeypoints:Thedensityofpurewater:____________.1,000kg/m3(onecubicmetre)(1,000kilogrammes)Marineanimalsandplantstakeadvantageofthedensityofwater.Whatdodifferentdensitiesintheoceanresultin?Waterintheoceanisalwaysmoving.WavesDidyouknow...90%ofyourlungsiswater?85%ofyourbloodiswater?75%ofyourbrainiswater?70%ofyourskiniswater?Nothingisas___________asadropofwater.preciousDiscussion:Whatcanwedotosavewaterinourdailylife?