生物多样性英文

shipsofdesert

--exposition

第一页，共二十五页。expositionExpositionisexplanatorywriting.ItspurposeistoexplainorclarifyapointPatternsofexposition:exemplification;processanalysis;causeeffectanalysis;comparisonandcontrast;classification;analogy;definition.

第二页，共二十五页。OrganizationPart1(para.1-8):thelistoftheimagesofenvironmentaldestruction:thedryingupoftheAral;deforestation;airpollutionPart2(para.9-16):analysisoftheglobalthreatsposedbytheenvironmentaldestructionandthecommoncause---thechangeintherelationshipbetweenhumancivilizationandtheearth’snaturalbalancePart3(para.17-26):thesolutiontoenvironmentaldestructions---reinventingandhealingtherelationshipbetweencivilizationandtheearth第三页，共二十五页。Lossofbiodiversity第四页，共二十五页。Biodiversity（生物多样性）Definition：Biologicaldiversity(biodiversity)referstoarangeofdiverselivingorganisms(animals,plants,micro-organisms)onaregularbasisconstitutedbythecombinationofstableecologicalcomplexes.第五页，共二十五页。Valueofbiodiversityanditssignificance：Directvalue：（1）biodiversityprovidesfood,fiber,buildingmaterialsandfurniture,andotherindustrialrawmaterialsforhumanbeings.第六页，共二十五页。（2）Biodiversityalsohaveaestheticvalue（美学价值）,wecancultivateoursentimentsandbeautifypeople’slives.Inaddition,biodiversitycanalsostimulateinspirationforliteraryandartisticcreation.wintersweet

第七页，共二十五页。chrysanthemum第八页，共二十五页。bamboo第九页，共二十五页。（3）Biodiversityhasanimportantecologicalfunction.Nomatterwhatkindofecosystem,wildlifeisoneoftheessentialcomponents.Wildlifeoncereduced,theecosystemstabilitywouldbedestroyed,thesurvivalenvironmentofmankindwouldalsobeaffected.第十页，共二十五页。thepotentialvalue:

asfarasthemedicinalproperties,80%ofthepopulationsindevelopingcountriesrelyonplantsoranimals,toensurethebasichealth.第十一页，共二十五页。第十二页，共二十五页。第十三页，共二十五页。Causesofbiodiversityreduction:1、Therapidincreaseinpopulation.第十四页，共二十五页。Thepopulationkeepsincreasing,soarablelandmustbeexpandedtomeetdemandsofeating,thisbecomesthedirectthreattothenaturaleco-systems.第十五页，共二十五页。2、Overexploitation

第十六页，共二十五页。Environmentalpollution

第十七页，共二十五页。killing第十八页，共二十五页。第十九页，共二十五页。No!!!第二十页，共二十五页。Aretheseproblemsdiffic