新视角研究生英语读说写2三单元课后练习答案

•ExercisesReadingComprehensionStructureoftheTextUnit3:ExercisesVocabularyClozeTranslationUnit3:Readingcomprehension1.Inparagraph1,theauthorsaysthatweareinthemiddleofasixthgreatextinction.Whatarethesegreatextinctions?Couldyounamesome.Inwhatwayisthecurrentgreatextinctiondifferentfromthepreviousfiveones?Thedifferenceliesinthefactthatthepreviousfivegreatextinctionshaveoccurredfornaturalcauses,butthecurrentgreatextinctionhasbeencausedbyhumanactivities.ReferenceEx.I,p.50Unit3:Readingcomprehension2.Whatistheauthortryingtodowithparagraph2?Theauthorgivesussomeexamplestoshowwhathumanneedshavecausedthecurrentgreatextinction.Generallyspeaking,theyarehumans’needsforsurvival.ReferenceUnit3:Readingcomprehension3.WhydidthebuffaloandthepassengerpigeoninNorthAmericabecomeextinct?Boththebuffaloandthepassengerpigeonbecameextinctowingtooverhuntingbyhumans.ReferenceUnit3:Readingcomprehension4.WhatpointdoestheauthorwanttoillustratebywritingabouttheEuropeanrabbitsinparagraph4?Hewantstoillustratethatnaturalhabitatsofsomenativespeciescouldbedestroyedbytheintroductionofforeignspecies.TheintroductionofEuropeanrabbitsintoAustraliaisagoodexample.TheymultipliedquicklyandthreatenedthehabitatofnativegrazinganimalsinAustraliabyeatingallthevegetation.ReferenceUnit3:Readingcomprehension5.Inparagraph5,theauthorstatesthathumansendangerotherspeciesbydestroyingtheirnaturalhabitats.Whatexampledoestheauthorgivetosupportthisstatement?Theexampleis:Therapidshrinkingofrainforestcausedthelossofmanyspeciesthatmadetheirhomesinit.ReferenceUnit3:Readingcomprehension6.Whatcanwelearnfromparagraph8?Eachlifeformoccupiesaspecialplaceintheecosystem,andthedisappearanceofanyspecieswillaffectotherspeciesintheecosystem.But74speciesaredyingouteveryday.ReferenceUnit3:Readingcomprehension7.Whatarethetwoadvantagesthatbiodiversityhasovermonoculturesaccordingtoparagraphs9–12?1)Biodiversitymakesitpossibleforusefulsubstancestobefoundinspecieswehaven’tgottotestorstudy.2)Biodiversitywillsavehumanityfrombeingstarvedtodeathowingtotheirgreatdependenceonasmallnumberofspecies.ReferenceUnit3:Readingcomprehension8.Inparagraph10,theauthorwritesaboutthePacificyewtree.WhatmakesthePacificyewtreesohighlyvaluedtoday?Whatdoestheauthorwanttotellusbymentioningthistree?BecauseitisdiscoveredthatthebarkofthePacificyewtreecontainsasubstancecalledtaxol,whichcaneffectivelytreatcertainkindsofcancer.Bymentioningthistree,theauthorwantstotellusthatmanyspeciesmaydieoutbeforetheirvalueisdiscovered.ReferenceUnit3:Readingcomprehension9.Whatisthemainideaofparagraph11?Paragraph11mainlytellsusthatthevalueofthevastmajorityofspecieshasyettobediscovered.Itisveryimportantforustoprotectthediversityofspecies.Ifwedon’t,wewilllosespeciesthatmayturnouttobeextremelyimportanttoourownsurvival.ReferenceUnit3:Readingcomprehension10.Whatpointissuggestedbythelastparagraph?Itsuggeststhatit’shardtotellwhethertheseprotectivemethodswillbeeffectiveornotnowbecausetherapidhumanpopulationgrowthmaymakeitdifficulttoputthesemethodsintopractice.Reference1.Introduction(Paras.1–2)2.Body(Paras.3–15)3.Conclusion(Para.16)TextOutlineUnit3:StructureofthetextEx.II,p.511.Introduction(Paras.1–2)Weareinthemiddleofasixthgreatextinction,whichiscausedby_______________.TextOutlineUnit3:Structureofthetexthumanactivities2.Body(Paras.3–15)1)_________________thathumanactivitiesendangerotherspecies.(Paras.3–5)TextOutlineUnit3:StructureofthetextThreemajorways2)Thereasonswhyweshouldpreserveeverylife-formonearth.(Paras.6–13)3)Methodsofprotectingendangeredspecies.(Paras.14–15)2.Body(Paras.3–15)TextOutlineUnit3:Structureofthetext1)_________________thathumanactivitiesendangerotherspecies.(Paras.3–5)ThreemajorwaysA.Humanbeings____________________fortheirmeat,bones,skinsorforprotectingtheircropsandlivestock.B.Foreignspeciesintroducedbyhumanbeingscan__________________________________.C.Humanbeings____________________________bycuttingdownforests,buildingtowns,etc.killoffanimalsdirectlyendangerthehabitatofnativespeciesdestroyanimals’naturalhabitats2.Body(Paras.3–15)2)Thereasonswhyweshouldpreserveeverylife-formonearth.(Paras.6–13)TextOutlineUnit3:StructureofthetextA._____________________________.B.Thevarietyofspeciescanaddnaturalbeauty.C.Somespeciesprovidehumanswitheconomicvalue.D.Eachlife-form_________________________________.E.Biodiversityhasobviousadvantagesover____________.Everylife-formhasarighttoexistoccupiesaplacewithinitsecosystemmonocultures2.Body(Paras.3–15)3)Methodsofprotectingendangeredspecies.(Paras.14–15)TextOutlineUnit3:StructureofthetextA.____________.B._____________________________________.C.Protectinganimalsthroughcaptivebreeding(zoos).PassinglawsSettingasidenationalparksandpreservesTextOutlineUnit3:Structureofthetext3.Conclusion(Para.16)WeIt’shardtotelltheeffectivenessoftheseprotectivemethodsnow.Thebiggestproblemremains_______________________________________________.howtomeettheneedsofagrowinghumanpopulation1.Thepassengerpigeonwasa______exampleofaspeciesthatwasmadeextinctbyoverhunting.primeUnit3:Vocabularycomponentmonoculturemultiplyconservepri