英美文化背景与国家概况之美国地理

WhiteHouse2011生物技术王传鑫2114122259contents(156-162)1、LandResource2、RiversandLakes3、ForestsandMineralResources4、NewProblemsUncleSamSatellitemapofAmerica卫星地图中的美国TopographicmapoftheUnitedStatesofAmerica美国地形图LandResourceAbout47%ofAmerica’slandareacanbeusedforagriculturalpurposes，including400millionacresofarable（适于耕种的）croplandand900millionacresofpermanentpastureland（牧场）。ThemainriversandmountainsofAmericaRiversandlakesMississippiRiver,itflowsabout6400kilometersfromitsnorthwesternsourceintheRockiestotheGulfofMexico,ItstributariesincludenearlyalltheriverswestoftheAppalachianmountains(阿帕拉契山脉)andtheeastoftheRockies.BigsteamshiponMississippiMississippiBigdamonMississippiRockiesPotomacriver(波托马克河),itisfamousnotonlybecauseWashingtonD.C,itisregardedasthetraditionaldividinglinebetweentheSouthandtheNorth.ThesceneryofPotomacriverThesceneryofPotomacriverGrandCanyon(科罗拉多大峡谷)Greatlakes,ofthesefivelakesonlyone,LakeMichigan,belongstoAmericacompletelywhiletheotherfouraresharedwithCanada.Thesefivelakes,withanareaofabout240000squarekilometers,constitutethelargestlakegroupintheworld.Greatlakes五大湖Greatlakes五大湖LakesuperiorLakeMichiganLakeHuronLakeErieLakeOntarioNiagaraFallsThefivelakesslopedownwardtowardstheeast.LakeErieisover100metershigherthanLakeOntarioandtheriverthatconnectsthemiscalledNiagara（尼亚加拉）River.ThesteepdropinelevationgivesbirthtotheNiagaraFalls,itattractslargenumbersofvisitorsfromaroundtheworld.NiagaraFallsNiagaraFallsThebiggestfallsintheworldNiagaraFallsNiagaraFallsAmericahasbeenknownforitsrichforestresources.WhenthefirstEuropeancolonistsarrived,Americawasstillcoveredwithdenseforests,stretchingabout1600kilometersinland(国内的)fromtheAtlanticCoastline.Todayaboutone-thirdoftheUnitedStatesisstillcoveredwithforestsThedistributionoftheforestsForestsandMineralResourcesThebiggesttreeintheworldSequoia(红杉)3000yearsoldDiameter：6metersTowers：100metersTheUnitedStatesisrichinmineralresources.Itranksamongthecountrieswiththegreatestreserves(储藏量)ofcoal,ironore,andoil.Italsoabounds(富于)inlead（铅）,copper（铜）,zinc（锌）,gold,aluminum（铝）,phosphate（磷酸）rock,andsilver.NewProblemsofmodernAmericaAfterthesecondworldwar,Americachangedfromanationthatexportedrawmaterialsintoonethatimportedthesecommodities(商品).Excessiveexplorationsandlargeconsumptionhaveexhaustedmanyresourcesthatarenotrenewable.Alaskaisrichinoil,butintermsofagriculture,itisstillan“icebox”Nowabout90%mineralsmostnecessarytothecountryarepartiallyimportedfromabroad.Largeimportationofrawmaterials，especiallyoil，isthemajorcauseofAmerica’sgrowingdeficit（赤字）inforeigntrade.DependenceonimportedrawmaterialrenderstheUSeconomyvulnerable（易受影响的）toimpactsresultingfromunsteadysupplies.ThankyouforyourwatchingStatueofliberty