AsGilbertWhite，Darwin，andothersobservedlongago，allspeciesappeartohavetheinnatecapacitytoincreasetheirnumbersfromgenerationtogeneration.Thetaskforecologistsistountangletheenvironmentaandbiologicalfactorsthatholdthisintrinsiccapacityforpopulationgrowthincheckoverthelongrun.Thegreatvarietyofdynamicbehaviorsexhibitedbydifferentpopulationmakesthistaskmoredifficult：sompopulationsremainroughlyconstantfromyeartoyear;othersexhibitregularcyclesofabundanceandscarcity;stillothersvarywildly，withoutbreaksandcrashesthatareinsomecasesplainlycorrelatedwiththeweather，andinothercasesnot.Toimposesomeorderonthiskaleidoscopeofpatterns，oneschoolofthoughtproposesdividingpopulationsintotwogroups.Theseecologistspositthattherelativelysteadypopulationshavedensity-dependentgrowthparameters;thatis，ratesofbirth，death，andmigrationwhichdependstronglyonpopulationdensity.Thehighlyvaryingpopulationshavedensity-independentgrowthparameters，withvitalratesbuffetedbyenvironmentalevents;theseratesfluctuateinawaythatiswhollyindependentofpopulationdensity.Thisdichotomyhasitsuses，butitcancauseproblemsiftakentooliterally.Foronething，nopopulationcanbedrivenentirelybydensity-independentfactorsallthetime.Nomatterhowseverelyorunpredictablybirth，death，andmigrationratesmaybefluctuatingaroundtheirlong-termaverages，iftherewerenodensity-dependenteffects，thepopulationwould，inthelongrun，eitherincreaseordecreasewithoutbound(barringamiraclebywhichgainsandlossescanceledexactly)。Putanotherway，itmaybethatonaverage99percentofalldeathsinapopulationarisefromdensity-independentcauses，andonlyonepercentfromfactorsvaryingwithdensity.Thefactorsmakinguptheonepercentmayseemunimportant，andtheircausemaybecorrespondinglyhardtodetermine.Yet，whetherrecognizedornot，theywillusuallydeterminethelong-termaveragepopulationdensity.Inordertounderstandthenatureoftheecologist’sinvestigation，wemaythinkofthedensity-dependenteffectsongrowthparametersasthesignalecologistsaretryingtoisolateandinterpret，onethattendstomakethepopulationincreasefromrelativelylowvaluesordecreasefromrelativelyhighones，whilethedensity-independenteffectsacttoproducenoiseinthepopulationdynamics.Forpopulationsthatremainrelativelyconstant，orthatoscillatearoundrepeatedcycles，thesignalcanbefairlyeasilycharacterizedanditseffectsdescribed，eventhoughthecausativebiologicalmechanismmayremainunknown.Forirregularlyfluctuatingpopulations，wearelikelytohavetoofewobservationstohaveanyhopeofextractingthesignalfromtheoverwhelmingnoise.Butitnowseemsclearthatallpopulationsareregulatedbyamixtureofdensity-dependentanddensity-independenteffectsinvaryingproportions.
1.Theauthorofthetextisprimarilyconcernedwith
[A]Discussingtwocategoriesoffactorsthatcontrolpopulationgrowthandassessingtheirrelativeimportance.
[B]Describinghowgrowthratesinnaturalpopulationsfluctuateovertimeandexplainingwhythesechangesoccur.
[C]Proposingahypothesisconcerningpopulationsizeandsuggestingwaystotestit.
[D]Posingafundamentalquestionaboutenvironmentalfactorsinpopulationgrowthandpresentingsomecurrentlyacceptedanswer.
2.Itcanbeinferredfromthetextthattheauthorconsidersthedichotomydiscussedtobe
[A]Applicableonlytoerraticallyfluctuatingpopulations.
[B]instrumental，butonlyifitslimitationsarerecognized.
[C]Dangerouslymisleadinginmostcircumstances.
[D]Acompleteandsufficientwaytoaccountforobservedphenomena.
3.tothetext，allofthefollowingbehaviorshavebeenexhibitedbydifferentpopulationsEXCEPT
[A]Roughlyconstantpopulationlevelsfromyeartoyear.
[B]Regularcyclesofincreasesanddecreasesinnumbers.
[C]Erraticincreasesinnumberscorrelatedwiththeweather.
[D]Uncheckedincreasesinnumbersovermanygenerations.
4.Thediscussionconcerningpopulationinthethirdparagraphservesprimarilyto
[A]Demonstratethedifficultiesecologistsfaceinstudyingdensity-dependentfactorslimitingpopulationgrowth.
[B]Advocatemorerigorousstudyofdensity-dependentfactorsinpopulationgrowth.
[C]Provethatthedeathratesofanypopulationareneverentirelydensity-independent.
[D]underlinetheimportanceofevensmalldensity-dependentfactorsinregulatinglong-termpopulationdensities.
5.Inthetext，theauthordoesallofthefollowingEXCEPT
[A]Citetheviewsofotherbiologists.
[B]Defineabasicproblemthatthetextaddresses.
[C]Presentconceptualcategoriesusedbyotherbiologists.
[D]Describetheresultsofaparticularstudy.
更新时间:2024-11-23 23:00:16ABDDD
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Itisnecessarythatthestudents____moreexcercisestodo.
WeexpectMr.Whitewill____ClassOnewhenMissJaneretires.
____whatmay,we’renotgoingtomakeanyconcessionstohisunreasonabledemands.
Hiscompanionshavethreatenedto__hiscrimestothepolice.
RogerRosenblatt’sbookBlackFiction,inattemptingtoapplyliteraryratherthansociopoliticalcriteriatoitssubject,successfullyalterstheapproachtakenbymostpreviousstudies.AsRosenblattnotes,criticismofBlackwritinghasoftenservedasapretextforexpoundingonBlackhistory.AddisonGayle’srecentwork,forexample,judgesthevalueofBlackfictionbyovertlypoliticalstandards,ratingeachworkaccordingtothenotionsofBlackidentitywhichitpropounds.Althoughfictionassuredlyspringsfrompoliticalcircumstances，itsauthorsreacttothosecircumstancesinwaysotherthanideological,andtalkingaboutnovelsandstoriesprimarilyasinstrumentsofideologycircumventsmuchofthefictionalenterprise.Rosenblatt’sliteraryanalysisdisclosesaffinitiesandconnectionsamongworksofBlackfictionwhichsolelypoliticalstudieshaveoverlookedorignored.WritingacceptablecriticismofBlackfiction,however,presupposesgivingsatisfactoryanswerstoanumberofquestions.Firstofall,isthereasufficientreason,otherthanthefacialidentityoftheauthors,togrouptogetherworksbyBlackauthorsSecond,howdoesBlackfictionmakeitselfdistinctfromothermodernfictionwithwhichitislargelycontemporaneousRosenblattshowsthatBlackfictionconstitutesadistinctbodyofwritingthathasanidentifiable，coherentliterarytradition.LookingatnovelswrittenbyBlackoverthelasteightyyears,hediscoversrecurringconcernsanddesignsindependentofchronology.Thesestructuresarethematic,andtheyspring,notsurprisingly,fromthecentralfactthattheBlackcharactersinthesenovelsexistinapredominantlywhiteculture,whethertheytrytoconformtothatcultureorrebelagainstit.BlackFictiondoesleavesomeaestheticquestionsopen.Rosenblatt’sthematicanalysispermitsconsiderableobjectivity;heevenexplicitlystatesthatitisnothisintentiontojudgethemeritofthevariousworksDyethisreluctanceseemsmisplaced,especiallysinceanattempttoappraisemighthaveledtointerestingresults.Forinstance,someofthenovelsappeartobestructurallydiffuse.Isthisadefect,oraretheauthorsworkingoutof,ortryingtoforge,adifferentkindofaestheticInaddition,thestyleofsomeBlacknovels,likeJeanToomey’sCane,vergesonexpressionismorsurrealism;doesthistechniqueprovideacounterpointtotheprevalentthemethatportraysthefateagainstwhichBlackheroesarepitted,athemeusuallyconveyedbymorenaturalisticmodesofexpressionInspiteofsuchomissions,whatRosenblattdoesincludeinhisdiscussionmakesforanastuteandworthwhilestudy.BlackFictionsurveysawidevarietyofnovels,bringingtoourattentionintheprocesssomefascinatingandlittle-knownworkslikeJamesWeldonJohnson’sAutobiographyofanEx-ColoredMan.Itsargumentistightlyconstructed,anditsforthright,lucidstyleexemplifieslevelheadedandpenetratingcriticism.
1.Theauthorofthetextisprimarilyconcernedwith__________.
[A]Evaluatingthesoundnessofaworkofcriticism.[B]Comparingvariouscriticalapproachestoasubject.
[C]Discussingthelimitationsofaparticularkindofcriticism.
[D]Summarizingthemajorpointsmadeinaworkofcriticism.
2.TheauthorofthetextbelievesthatBlackFictionwouldhavebeenimprovedhadRosenblatt__________.
[A]EvaluatedmorecarefullytheideologicalandhistoricalaspectsofBlackfiction.
[B]AttemptedtobemoreobjectiveinhisapproachtonovelsandstoriesbyBlackauthors.
[C]ExploreingreaterdetailtherecurrentthematicconcernsofBlackfictionthroughoutitshistory.
[D]Assessedtherelativeliterarymeritofthenovelsheanalyzesthematically.
3.author’sdiscussionofBlackFictioncanbebestdescribedas__________.
[A]Pedanticandcontentious.
[B]Criticalbutadmiring.
[C]Ironicanddeprecating.
[D]Argumentativebutunfocused.authorofthetextemploysallofthefollowinginthediscussionofRosenblatt’s
4.bookEXCEPT：__________.
[A]Rhetoricalquestions.
[B]Specificexamples.
[C]Comparisonandcontrast.
[D]Definitionofterms.
5.TheauthorofthetextreferstoJamesWeldonJohnson’sAutobiographyofanEx-ColoredManmostprobablyinorderto__________.
[A]pointoutaffinitiesbetweenRosenblatt’smethodofthematicanalysisandearliercriticism.
[B]Clarifythepointaboutexpressionisticstylemadeearlierinthepassage.
[C]QualifytheassessmentofRosenblatt’sbookmadeinthefirstparagraphofthepassage.
[D]giveaspecificexampleofoneoftheaccomplishmentsofRosenblatt’swork.
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