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.

You____thatlettertoJames.However，youdidn't.

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.

_____himtomorrow.

Allofuswouldhaveenjoyedthepartymuchmoreifthere_____quitesuchacrowdofpeoplethere.