PARTVREADINGCOMPREHENSION

Inthissectiontherearefourpassagesfollowedbyquestionsorunfinishedstatements,eachwithfoursuggestedanswersmarkedA,B,CandD.Choosetheonethatyouthinkisthebestanswer.

TEXTA

Racket,dinclamor,noise,whateveryouwanttocallit,unwantedsoundisAmerica'smostwidespread

nuisance.Butnoiseismorethanjustanuisance.Itconstitutesarealandpresentdangertopeople'shealth.Day

andnight,athome,atwork,andatplay,noisecanproduceseriousphysicalandpsychologicalstress.Nooneis

immunetothisstress.Thoughweseemtoadjusttonoisebyignoringit,theear,infact,neverclosesandthe

bodystillresponds—sometimeswithextremetension,astoastrangesoundinthenight.

Theannoyancewefeelwhenfacedwithnoiseisthemostcommonoutwardsymptomofthestressbuilding

upinsideus.Indeed,becauseirritabilityissoapparent,legislatorshavemadepublicannoyancethebasisof

manynoiseabatementprograms.Themoresubtleandmoreserioushealthhazardsassociatedwithstress

causedbynoisetraditionallyhavebeengivenmuchlessattention.Nevertheless,whenweareannoyedormade

irritablebynoise,weshouldconsiderthesesymptomsfairwarningthatotherthingmaybehappeningtous,

someofwhichmaybedamagingtoourhealth.

Ofmanyhealthhazardstonoise,hearinglossisthemostclearlyobservableandmeasurablebyhealth

professionals.Theotherhazardsarehardertopindown.Formanyofus,theremaybeariskthatexposuretothe

stressofnoiseincreasessusceptibilitytodiseaseandinfection.Themoresusceptibleamongusmayexperience

noiseasacomplicatingfactorinheartproblemsandotherdiseases.Noisethatcausesannoyanceandirritability

inhealthpersonsmayhaveseriousconsequencesforthesealreadyillinmindorbody.

Noiseaffectsusthroughoutourlives.Forexample,thereareindicationsofeffectsontheunbornchildwhen

mothersareexposedtoindustrialandenvironmentalnoise.Duringinfancyandchildhood,youngstersexposed

tohighnoiselevelsmayhavetroublefallingasleepandobtainingnecessaryamountsofrest.

Why,then,istherenotgreateralarmaboutthesedangers?Perhapsitisbecausethelinkbetweennoiseand

manydisabilitiesordiseaseshasnotyetbeenconclusivelydemonstrated.Perhapsitisbecausewetendto

dismissannoyanceasapricetopayforlivinginthemodernworld.Itmayalsobebecausewestillthinkof

hearinglossasonlyanoccupationalhazard.

1.InParagraph1,thephrase"immuneto"areusedtomean___.

A.unaffectedby

B.hurtby

C.unlikelytobeseenby

D.unknownby

2.Theauthor'sattitudetowardnoisewouldbestbedescribedas___.

A.unrealistic

B.traditional

C.concerned

D.hysterical

3.Whichofthefollowingbeststatesthemainideaofthepassage?

A.Noiseisamajorproblem;mostpeoplerecognizeitsimportance.

B.Althoughnoisecanbeannoying,itisnotamajorproblem.

C.Noiseisamajorproblemandhasnotyetbeenrecognizedassuch.

D.Noiseisamajorproblemaboutwhichnothingcanbedone.

4.Theauthorcondemnsnoiseessentiallybecauseit___.

A.isagainstthelaw

B.canmakesomepeopleirritable

C.isanuisance

D.inagangertopeople'shealth

5.Theauthorwouldprobablyconsiderresearchabouttheeffectsnoisehasonpeopletobe___.

A.unimportant

B.impossible.

C.awasteofmoney

D.essential

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.

Writing：

PiracyisstillaseriousprobleminChina.Writeacompositionofabout400wordstostateyourview.

As____clearfromhismanners,heisateacher.

Theradiois________astrangesignal.What’swrongwithit?