高二英语课件高二英语下学期Unit16thesea旧人教版高二英语课件

Seenfromspace,theearthlooksblue.Twothirdsoftheearth’ssurfaceismadeupofvastoceans.PartOneTheSea1Charactersofthesea(1)Vastandblue(2)saltycontains35partsofsaltperthousandpartsofwater----3.5%byweight11othermineralsmakeupthewater(3)cleanSeaweedsproducevariouschemicals2TheMediterranean(1)longmorethan3700km(2)wide1800kmatitswidestpoint(3)warmcanreachupto25°Coreven29°C(4)salty37and39partsofsaltperthousand3.7%and3.9%byweightTheMediterraneanQuestion:Whydoesittake80yearsforMediterraneanwatertobechangedwithAtlanticwater?OnlyonenarrowentranceTheAtlantic3coralbedsCoralisnotaplantbutavarietyofanimallifeofdifferentshapesandbrightcolors.Certainconditionsforcoraltolive(1)Watertemperatureabove20°C(2)Plentyoflight(3)Clearwater(4)Depthoflessthan60metersLet’slookatbeautifulcoralThelongestcoralbedintheworldItliesoffthenortheastcoastofAustralia,about2010kilometerslong.ParttwoSaltlakes1theGreatSaltLake---thesaltiestlake,27%byweight,intheUSA2theDeadSea---intheMiddleEastLow-lying:ataround395metersbelowsealevel,thelowestlake,alsothelowestplaceintheworldSalty:25%byweight,difficulttoswimordiveQuestion1:WhyistheDeadSeasosalty?(1)Waterislostintheairwhilesaltstays(2)Thereisverylittlerain,merely60mminayearonaverage(3)OncethemineralsfromhundredsofnaturalspringsandtheRiverJordanflowintotheDeadSea,theystayinthelake.Quesion2:WhyisitcalledtheDeadSea?Becauseveryfewthingscanliveinsuchsaltywater.Butitisverybeautiful.DiscussionWhyareseassoimportant?HowcanpeoplemakeuseoftheSea?Whatshouldwedowithit?Somesuggestions1fishing2oilandgasexploiting3spaceusing4transportationandportconstruction5seasprotectionetc.Languagepoints1Seenfromspace,theearthlooksblue.seenfromspace过去分词做状语，相当于一个状语从句。如Foldedupalongthelines,thepaperwillbealittlebox.______moretime,wecandoitbetter.(give)2Thisisbecausetwothirdsoftheearthismadeupofvastoceans.(1)makeup组成，编制，弥补等e.g.Theteamwasmadeupoftwelveplayers,acoachandadoctor.Heisexpertatmakingupstories.Youshouldmakeupthelosttime.(2)because,as的区别because的语气最强，是必然的因果关系，较正式。当回答why提问的问句时，只能用because.As多用于日常的交谈中，表双方都了解的原因，常位于句首。e.g.Asitisraining,you’dbettertakeataxi.Given3Mostoftheoceanscontains35partsofsaltperthousandpartsofwater.Thatis3.5%byweight.byweight按重量计算，介词by的意思是“按照”“依照”e.g.Thepackageischargedbyweight.包裹按重量收费。如果后面跟单位词，则要加thee.g.InEngland,sugarissoldbythepound,eggsbythedozen,andclothbytheyard.这些工人按日付工资，我们是按月付工资。—————————————————————————Theseworkersarepaidbytheday,butwearepaidbythemonth.4theMediterranean,theAtlantic,theDeadSea等在江，河，湖，海等名词前一般要加定冠词。但当其做定语时，则不可用定冠词，如Mediterraneanwater（地中海的水）,Atlanticwater等5Thereislittlerainhere,merely60mminayearonaverage.on(the)average是固定词组，表示“平均起来，一般来说”的意思e.g.Onaverage,shereceives5letterseachday.而average可以做名词，也可以做形容词。Let’sprotectourseasandourearth.