GriffithworkedforafirmthatspecializedineconomicdevelopmentinWashingtonD.C.becausesheneededmoneytopayforherdebt.

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.

Breadandbutter____likedbyWesterners.

PartIReadingComprehension

Directions:Inthisparttherearefourpassages.Eachpassageisfollowedbyfourcomprehensionquestions.Readthepassageandanswerthequestions.ThenmarkyouranswerontheAnswerSheet.

Passage1

Questions1to5arebasedonthefollowingpassage:

Someyearsagothecaptainofashipwasveryinterestedinmedicine.Healwaystookmedicinebookstoseaandlikedtotalkaboutdifferentdiseases.

Onedayalazysailoronhisshippretendedtobeill.Helayonhisbunk(铺)andgroanedasifhewereverysick.Thecaptaincametoseehimandwasverypleasedtohaveapatienttolookafter.Hetoldthemantorestforafewdaysandmadetheothersailorsdohiswork.Threedayslateranothersailorpretendedthathehadsomethingwrongwithhischest.Oncemorethecaptainlookedinhismedicalbooksandtold“sick”mantohavearest.

Theothersailorswereveryangrybecausetheyhadmoreworktodo.Thepatientshadthebestfoodandlaughedattheirfriendswhenthecaptainwasnotlooking.Atlastthemate(船长副手)decidedtocurethe“sick”men.Hemixedupsomesoap,soot(烟灰),glue(胶水)andotherunpleasantthings.Thenheobtainedpermissionfromthecaptaintogivehismedicinetothe“sick”men.Whentheytastedthemedicine,theyreallydidfeelill.Itwassohorriblethatoneofthepatientsjumpedoutofhibunk,ranupondeskandclimbedthehighestmastontheship.Hedidnotwantanymoremedicine.

Thematetoldbothofthementhattheymusttakethemedicineeveryhalfanhour,nightandday.Thissooncuredthem.Theybothsaidtheyfeltbetterandwantedtostartwordagain.Thecaptainrealizedthatthementriedtodeceivehimsohemadethemworkveryhardfortherestofthevoyage.

1.Thefirstsailorpretendedtobeillbecausehewantedto.

A.testthecaptain’sknowledgeofmedicineB.befreefromwork

C.havethebestfoodontheshipD.playajokeonhisfriends

2.Whenthecaptainknewasailorwasill,he.

A.didn’tcaremuchB.sentforadoctor

C.lookedafterhimandtoldhimtohavearestD.gavehimsomemedicine

3.Thepatientsfeltbetterquicklybecause.

A.theyhadbeengivenpropermedicine

B.theylearnedthatthecaptainhadfoundoutthetruth

C.theywerelaughedatbytheirfriends

D.themedicinethemategavewashorrible

4.Whenthecaptainknewhehadbeendeceived,he.

A.toldthemnottodosoagainB.losthistemper

C.madethemworkharderD.firedthem

5.Whichofthefollowingbestsummarizesthepassage?

A.AsuddenCure.B.TwoPatients.C.CaptainandSailors.D.ADifficultVoyage.

WhenthepoliceofficerswhotookpartintheKingbeatingwerefirstbroughtto___________,theirlawyersusedthevideotapeasevidenceagainsttheprosecution.