托福模拟考试及答案解析20

托福模拟考试及答案解析（20）

（1~6/共51题）阅读理解

TheFormationoftheSolarSystem

Astronomersestimatethatthesolarsystemissomewherearoundfivebillionyearsoldand

haveseveraltheoriesregardingitscreation.Themostcommon—andmostwidelyaccepted—one

isthenebularhypothesis.Accordingtothistheory,thesolarsystemdevelopedfroman

enormouscloudofgasanddust.Firstproposedintheeighteenthcentury,thenebularhypothesis

wasnotwidelyaccepteduntilthelatetwentiethcentury,whenobservationsofnewbornstars

andtheirsolarsystemsappearedtoconfirmmanyaspectsofit.

Thenebularhypothesispositsthatahugecloudofgasanddustbegancollapsingonitselfdue

totheforceofgravity.Asitcollapsed,theconservationofangularmomentumcausedthegas

anddusttocontractfurtherandtospinrapidly.Thisspinningcreatedacentralcoreof

elements—primarilyheliumandhydrogen—whichformedanewstar;orprotostar,thatwould

eventuallybecomethesun.Thecontractingelementsheatedup,andnuclearfusioninthe

protostarsoonoccurred.Aroundtheprotostar,alargefiatdiscofdust,rock,andice,which

wouldbecometheplanets,moons,andasteroidsinthesolarsystem,collected.Thisinitialstage

intheformationofthesolarsystemlastedapproximately100,000years.

Next,theplanetsformedthroughtheprocessknownasaccretion.Inthespinningdiscof

materialsurroundingtheprotostar,dust,rock,andicestartedslammingintooneanotherand

clumpingintobiggerandbiggermasses.Astheyincreasedinsize,theirgravitationalfields

attractedmorematerial,sotheygrewevenlarger.Overthecourseofseveralmillionyears,this

processformedtheplanets.Thoseplanetsclosesttothesunformedintoballsofrockymaterial

becauseonlyelementswithhighmeltingpoints,suchasiron,nickel,andvarioussilicates,could

endurethesun'sheat.

Theouterplanets,ontheotherhand,formedintogiantballsofgassinceinthecolderregion,

whichiscalledthefrostlinebyastronomersandwhichstartsbetweenMarsandJupiter,moreof

thespinningdisc'smaterialsurvivedthesun'sgrowingheat.Thismaterialmostlyexistedinthe

formofgasandicecrystals.Thespinningouterplanetscapturedlargeamountsofthismaterial

andsubsequentlygrewintomassiveballsofgasthatcontainedsomefrozenelements.

*posit:tostateasafact

*accretion:anincreaseinsizeduetothegradualaccumulationofmaterial

第1题

Theauthor'sdescriptionoftheprotostarinparagraph2mentionswhichofthefollowing?

A.Themannerinwhichitformedaccordingtothenebularhypothesis

B.Thesizethatitattainedbeforetheplanets,moons,andasteroidsformed

C.Thewaythatnuclearfusionhappenedandcausedittobecomethesun

D.Theamountoftimethatitspununtilitscentralcorewasformed

第2题

Accordingtoparagraph4,whichofthefollowingistrueofthefrostline?

A.TheplanetsthatarelocatedwithinittravelaroundthesunfrombeyondMars.

B.Astronomersbelievethatitistoocoldforanyformsoflifetosurviveinit.

C.AIIoftheplanetsinittooklongertocreatethantheplanetsclosertothesun.

□.Elementssuchasironandnickelarefoundonplanetsthereintheirgaseousforms.

第3题

Vocabulary

=todecreaseinsize

第4题

=anymineralcompoundcontainingsilicon

第5题

=tobecompletelyaroundsomeoneorsomething

第6题

=next;later;afterward

下一题

（7~21/共51题）阅读理解

EarthquakePrediction

Earthquakesrankamongthemostdevastatingof"allnaturaldisasters,andunlikemanyothers,

suchashurricanesandvolcaniceruptions,theyvirtuallyalwaysstrikewithnowarning.This

preventspeoplefromevacuatingtheearthquakezonetosavethemselves.Therehavebeen

someeffortstopredictearthquakes,buttheyarerifewithproblemsandhaveresultedonlyin

limitedsuccesses.

Onemethodistostudythelong-termhistoryofearthquakepatterns.Aroundtheworld,there

arecertainareas,suchasJapanandthePacificcoastregionoftheUnitedStates,where

earthquakesarefrequent.Thesezonesarelocatedalongfaultlines,whichmostlyoccurwhere

thetectonicplatescomprisingtheEarth'scrustmeet.Byexaminingthehistoricrecord,

seismologistscanmakegeneralpredictionsregardingfutureearthquakes.Additionally,an

increaseinseismicactivityinthesezonesmayindicatethepossibilityoflargerearthquakesinthe

nearfuture.Forexample,whenaminorearthquakeranking3.0ontheRichterscaleoccurs,there

isaroughlyten-percentchanceofalargeronehappeninginthesameareawithinafewdays.

Thisistoosmallamargintojustifythemassevacuationofpeoplefromapotentialearthquake

zonethough.

Makingmorespecificpredictionsofwhenandwhereearthquakeswilloccurisextremely

difficult.Oneareathathasseensomesmallsuccessisthestudyingofanimalbehaviorasanimals

tendtobesensitivetosuddenchangesintheirenvironments.PriortoanearthquakeinItalyin

2009,thepopulationofmaletoadsinaregionsuddenlymovedtonewterritories.Thiswaslater

citedasanexampleofanimalsforeseeinganearthquake.Unfortunately,usinganimalstopredict

earthquakesisunfeasibleatthistimeasitwouldrequireanenormouseffortcontinuouslyto

observeandreportonanimalpopulationsinearthquakezones.

Radongasemissionsmayenablescientiststopredictearthquakesinthefuture.Therehas

beenanotableriseinradongasemissionscomingfromundergroundpriortomanyearthquakes.

Apaperpublishedin2009showedthatsince1966,almostninetyearthquakeswereprecededby

radonemissionspikes.Someoftheseearthquakes,however,tookplacemonthsafterthe

emissionsoccurred,soitmaynotbepossibleaccuratelytostatewhentremorswillhappen.

Basedoncurrenttechnology,itappearsasthoughitisnotpossibletopredictearthquakeswith

anymeasureofaccuracy.

*tectonicplate:alargemassoflandthatisapartoftheEarth'scrust

*Richterscale:ascalethatgoesfrom1to10andmeasurestheintensityofearthquakes

第7题

Accordingtoparagraph2,whydoearthquakesoftentakeplaceinsomepartsoftheplanet?

A.Thepastoccurrenceofearthquakesmakesaregionmoresusceptibletotheminthefuture.

B.TheyoftenhappeninareaswherelargebodiesoflandmeettheEarth'soceans.

C.Theyoccurnearfaultlinesthatexistwheretheplatesmakingupthecrustmeet.

D.ThepresenceofvolcanoescanweakentheEarth'scrustandcauseearthquakestohappen.

第8题

Accordingtoparagraph3,oneproblemwithrelyinguponanimalstopredictearthquakesisthat

A.scientistsarenotsurewhichtypesofanimalstheyneedtoobservetheclosest

B.watchinggroupsofanimalswouldrequiretheexpenditureofnumerousresources

C.therearenotenoughpeoplewhoaretrainedtowatchhowanimalsbehave

D.howspecificgroupsofanimalsbehavepriortoearthquakesisnotyetknown

第9题

Vocabulary

=abundant;plentiful

第10题

=impractical

第11题

=apersonwhostudiesearthquakes

第12题

=tohappenbeforesomethingelse

第13题

Mapping

Thefollowingchartshowsthestructureofthepassage.Fillintheblankswiththeappropriate

words.

图片

第14题

Summary

Thefollowingisasummaryofthepassage.Fillintheblankswiththeappropriatewords.

Earthquakescanbedevastatingnaturaldisasters,butitisverydifficultto20them,unlike

hurricanesandvolcaniceruptions.Some21studythelong-termhistoryofearthquake

patterns.Certainplacesintheworldget22earthquakes,sotheycanpredictwheresome

earthquakeswilloccur.Additionally,whena3.0quakeonthe23scalehappens,thereisa

10%chancealargeronewilloccursoon.Animal24mayalsohelppredictearthquakes.In

Italyin2009,maletoadsmovedtonewterritories25toanearthquake.Andradongas

26oftenincreasebeforemanyearthquakes.However,allofthesemethodshaveproblems,so

predictingearthquakesmaynotbe27

第15题

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第17题

第18题

第19题

第20题

第21题

上一题下一题

（22~29/共51题）阅读理解

TheFormationoftheGlobalAtmosphere

Inmoderntimes,theEarth'satmosphereiscomprisedof78%nitrogen,21%oxygen,asmall

amountofcarbondioxide,andtraceamountsofseveralotherelements.Toreachthisstate,the

atmospherehasundergoneseveraltransformationsinitslonghistory.Inthebeginning,the

planethadnoatmosphere,but,astheEarthbegancooling,largeamountsofgaseswerevented

fromtheinterior;primarilythroughvolcanicactivity.Thismarkedthestartoftheplanet'sfirst

atmosphere.Duringthisstage,theatmospherecontainedmostlywatervapor,methane,carbon

dioxide,andnitrogen,amixturewhichcouldneverbesafelybreathedbyvirtuallyalllifeformson

theplanettoday.

AstheEarthcooledevenmore,thewatervaporintheatmospherefellfromtheskyasrain

andbegancollectingonthesurfaceroughlythreebillionyearsago.Itwasinthiswaterthatthe

firstformsoflifeappearedintheformofcyanobacteria,whichismorecommonlycalled

blue-greenalgae.Thesealgaefedoff"thehugeamountsofcarbondioxideintheatmosphere

and,throughtheprocessofphotosynthesis,emittedoxygenbackintotheatmosphere.Overthe

next300millionyears,thelevelofoxygenintheatmosphereroseinsmallamountsandattained

alevelsufficientenoughtobegincombiningwithironinrockstooxidizeandtoproducerust.

Throughthestudyofsuchrocks,geologistshavebeenabletopinpointtheearlyriseofthelevel

ofoxygenintheatmosphere.Infact,rocksabsorbedsomuchoftheoxygenproducedatthat

timethatthecreationofanoxygen-richatmospherewasforestalled.

Itwasapproximately750millionyearsagothatanoxygenboombeganontheplanet.A

tippingpointofsortswasreached,sotheoxygenlevelstartedoutpacingthecarbondioxidelevel

byclimbingtoaroundafifthofwhatitcurrentlyis.Thiswasasignificantenoughchangethatlife

formsdependingoncarbondioxidestarteddyingoutwhilethosefavoringoxygenstartedthriving.

Atthattime,alllifewasintheoceanssinceitcouldnotsurviveonlandonaccountofthehigh

levelsofultravioletradiationproducedbythesun.However,withtheincreaseintheoxygenlevel

oftheatmosphere,someoxygenmoleculeshitbythesun'senergybegansplittingintosingle

oxygenatoms.Thesesingleatomsthenformedwithairborneoxygenmolecules,whichhavetwo

atoms,toformozone,whichhasthreeoxygenatoms.Thisprocessgraduallyformedtheozone

layer;whichprotectslifeontheplanetfromhighdosesofultravioletradiation.

Oncetheozonelayerwasestablished,theworld'slifeforms,mostofwhichwereoxygen

breathing,graduallyemergedfromtheoceansandmigratedontotheland.Abalancebetween

thecarbondioxide-breathingplantsandoxygen-breathinganimalsslowlyasserteditself.Atthe

sametime,carbondioxidewasbeingabsorbednotonlybyplantsbutalsobytheoceansandrock

formationsinprocessesthatcontinuetothisday.Asaresult,thelevelofcarbondioxidedeclined

tolessthanonepercentoftheatmospherewhiletheamountofoxygenrose.Theendresultof

thisentireprocess,whichtookbillionsofyears,isthecurrentstateoftheatmosphere.

*trace:tiny;miniscule

*photosynthesis:theprocessthroughwhichplantsusethesun'senergytoconvertwaterand

carbondioxideintooxygenandsugarthattheyusefornourishment

*split:todivide

第22题

Vocabulary

=acolorless,odorless,andflammablegas

第23题

=tocombinewithoxygen

第24题

=asmallaquaticorganismthatcontainschlorophyll

第25题

=tomovefromoneplacetoanother

第26题

VocabularyQuestion

Thewordforestalledinthepassageisclosestinmeaningto

A.anticipated

B.hindered

C.produced

0.occasioned

第27题

FactualInformationQuestion

Accordingtoparagraph2,theoxygenlevelintheatmosphereincreasedbecause

A.certainrifeformsextractedcarbondioxidefromtheairandreleasedoxygenintoit

B.oxygenthathadbeenpreviouslycontainedinrocksescapedandmovedintotheatmosphere

C.thelightfromthesuncausedcompoundstobreakapartandtoreleasefree-standingoxygen

D.volcanicactivityaroundtheplanetreleasedlargeamountsofoxygenintotheair

第28题

NegativeFactualInformationQuestion

Inparagraph3,allofthefollowingquestionsareansweredEXCEPT:

A.WhatcausedtheozonelayertoformintheEarth'satmosphere?

B.Whydidnolifeexistontheplanet'ssurfacemorethan750millionyearsago?

C.Whendidtheoxygenlevelintheatmospherebegintoexceedthecarbondioxidelevel?

D.Howdidultravioletradiationlimitthesizeofthelifethatlivedintheplanet'soceans?

第29题

ProseSummaryQuestion

Anintroductorysentenceforabriefsummaryofthepassageisprovidedbelow.Completethe

summarybyselectingtheTHREEanswerchoicesthatexpressthemostimportantideasofthe

passage.Somesentencesdonotbelongbecausetheyexpressideasthatarenotpresentedinthe

passageorareminorideasinthepassage.

ThecompositionoftheEarth'satmospherehasundergoneseveralchangesoverthecourseof

theplanet'shistory.

ANSWERCHOICES

①Thecreationoftheozonelayerintheatmosphereenabledlifeformstoemergefromthe

oceansandtolivesafelyonland.

©Despitethefactthatnitrogendominatestheplanet'satmosphere,itcannotbesafelybreathed

bymostformsoflife.

③Thesun'sultravioletraysareharmfultoallformsoflifeandwouldkillitinarelativelyshort

periodoftimeifitwereexposedtotherays.

@Theearlyatmospherecontainedalargeamountofcarbondioxide,nitrogen,andother

elementstoxictomodernlifeforms.

⑤Theprocessofphotosynthesisthatwaspracticedbyalgaewaswhatpromptedoxygentobegin

enteringtheatmosphereinlargeamounts.

©TherewasagreatamountofvolcanicactivityontheEarthintheearlyyearsaftertheplanet

wasformed.

上一题下一题

（30~37/共51题）阅读理解

MoviesandTheatricalPerformances

Untilthecreatingofmotionpicturesinthelatenineteenthcentury,livetheatrical

performanceswereamongthemainwayspeopleentertainedthemselves.Nowadays,thereverse

istrueasmovieticketsalesandboxofficereceiptsfarexceedthoseoflivetheater.Whilethetwo

typesofperformanceshavesomesimilarities,theyarevastlydifferentinmanyways,andwhich

isthebetterofthetwodependsoneachperson'sindividualtasteandopinion.

Movieshaveseveraladvantagesoverlivetheatricalproductions,amongthembeingofmuch

greaterscope,havingcastsofthousandsinsomecases,andusingsophisticatedspecialvisualand

soundeffectstoenhancethestoriestheirdirectorswanttotell.Thestunningpresentations

createdareakeyreasonthatsomanypeopleworldwideenjoywatchingmovies.Therearealsoa

largenumberofgenres,sotherearelovestories,detectivestories,andevenstoriesabout

superheroes,whichmeansthereissomethingfornearlyeveryonetoenjoy.Moviescostlessto

attendthanmostlivetheatricalperformancesasticketsaveragearoundtendollarsashowwhile

livetheaterismuchmoreexpensive,withticketsforBroadwayproductionscostinghundredsof

dollarsormore.Finally,moviescanbeviewedathomeontelevisionsorcomputermonitors,

therebyeliminatingtheneedtogoouttobeentertained.

Livetheater;however;isnotwithoutmeritsofitsown.Foronething,itisamoreintimate

presentation,withtheaudienceandperformersbeinginthesameroomatthesametime,so

thereisamoreintenseconnectionthantheonepeoplegetfromwatchingactorsonfilm.

Theatricalperformancesandperformersalsotendtobeofhigherqualityactingwisesincethe

performersgetnosecondchanceiftheymakeamistake;movieactors,ontheotherhand,cando

asmanytakesasnecessarytogettheirlinesorscenesright.Iftheaterperformersflubtheirlines,

theaudiencewillnotice,andtheperformanceasawholewillsuffer.Asaresult,thebestactors

canbefoundinlivetheatricalperformances.Finally,inlivetheater;notwoperformancesare

everalike.Eachtimeaplay,opera,ballet,ormusicalisstaged,itmayutilizethesamewords,

songs,anddanceroutines,butthereisalwayssomethingfreshfortheaudiencetoappreciate.

Fromabusinesspointofview,moviestendtobemoreprofitablethanlivetheater.Moviescan

becopiedandviewedworldwidebymillionsofpeopleatthesametimeandtherebyearntheir

producersandstudiosenormousreturnsontheirinvestmentsinarelativelyshortamountof

time.Inrecentyears,forinstance,somemovieshavegrossedmorethanonebilliondollarsatthe

globalboxoffice.Livetheater;however;isstagedononenightinoneplaceatonetime,soits

earningpotentialislimitedbythenumberofseatsinthetheater.Whilesomemorepopular

performancesareputonindifferentcitiesatthesametime,therearestillfarfewer

simultaneousshowsthanmoviescanachieve.Mainlyonaccountofthewideraccessibilityof

moviesovertheatricalperformances,movieswilllikelycontinuetogrowinpopularitydespitethe

factthattheyareofpoorerqualitythantheatricalproductions.

*merit:value;excellence

*flub:toerr;tomakeamistake

*stage:toputonaperformanceheldonastage

第30题

Vocabulary

=tomakebetter;toimprove

第31题

=strongwithregardtofeelingsoremotions

第32题

=akindortype

第33题

=happeningatthesametime

第34题

InferenceQuestion

Whichofthefollowingcanbeinferredfromparagraph1abouttheatricalperformances?

A.Theyaresometimesperformedbyasmallcastofonlytwoorthreeactors.

B.Theymakelessmoneythanmoviesbutarestillabletobeprofitablefortheirproducers.

C.Theylostsomeoftheirpopularityinthetwentiethcenturyduetotheappearanceofmovies.

D.Theyareconsideredbetterthanmoviesbythemajorityofpeopleinmanycountries.

第35题

Inparagraph2,whydoestheauthormentionticketsforBroadwayproductions?

A.Tonotethedifficultyofacquiringthemforsomeofthemostpopularperformances

B.Ibstresshowexpensivetheyareincomparisontoticketsformovies

C.Toexplaintheprocessthatoneneedstogothroughtopurchasethem

D.Tbclaimthattheyareinaccessibletothemajorityofpeoplewhoseekentertainment

第36题

FactualInformationQuestion

Accordingtoparagraph4,whichofthefollowingistrueofmovies?

A.Someofthemhaveearnedmorethanonebilliondollarsinasinglecountryrecently.

B.Alotofthemfailtoearnmoney,buttheonesthatareprofitableearnhugesumsofmoney.

C.Theatricalperformancesfrequentlyearnmuchmoremoneythanmoviesdo.

D.Theycanproducelargeamountsofmoneyfortheirbackersveryquickly.

第37题

FillinaTableQuestion

Selecttheappropriatestatementsfromtheanswerchoicesandmatchthemtothetypeof

entertainmenttowhichtheyrelate.TWOoftheanswerchoiceswillNOTbeused.

图片.STATEMENTS

©Tendnottobeperformedbythebestactorsandactresses

②Aremanydifferenttypesofstoriesthatcanbepresentedtoaudiences

③Mayhaveslightdifferenceseachtimethattheyareseenbyaudiences

©Requireperformerstospendlongamountsoftimerehearsingtheirlines

⑤Havemuchlargercaststhantheothertypeofperformance

@Canbeshowntoasmallernumberofpeopleatthesametimethantheother

©Maytakeseveralmonthsofpreparationbeforeaudiencescanseethem上一题下一题

（38~51/共51题）阅读理解

White-CrownedSparrowVocalizations

Thewhite-crownedsparrowisasongbirdnativetoNorthAmericathatbreedsinAlaskaand

CanadainsummerandwintersinthecontinentalUnitedStatesandthenorthernpartofMexico.

Itisnotedforitsdistinctiveplumageconsistingofagraybreastandawhitecrownwithblack

streaks.Thesparrowisalsoeasilyrecognizedbyitsuniquesongandcallpatterns.These

vocalizationshavebeenatthecenterofsomeintensestudiesbyzoologists,theprimarypurpose

ofwhichwastorecognizewhenthebirdlearnshowtomakesongsandcalls.Asecondary

purposeofthestudieswastounderstandvariationsinthesongsandcallsthatoccurindifferent

geographicalregions.

Therearedistinctivesongsandcallsproducedbythesparrow,butonlythemalesofthe

speciesproducethesevocalizations.Thereareregionalvarietiesinthesongs,butallofthem

followasimilarpattern.First,thesparrowmakesahigh,piercingwhistleasanintroduction.This

isfollowedbymorewhistlesindifferentpatterns,andthenthebirdendsthesongwithanalmost

buzzingtrillingsound.Everysonglastsforonlytwotothreeseconds,andthebirdsingssongsin

groupsthatareseparatedbypausesofuptoeightorninesecondsbetweeneachone.Asforits

calls,thebirdhasaroundtendistinctivecalls.Theymaysoundsimilartothesongs,buttheyare

not.Instead,thecallsarecomposedofsharpwhistlesandchirpsthataremadeingroupsoras

individualnoisesseparatedbypauses.Thepurposesofthecallsvary,butthemostcommonare

alarmcallstowarnothersofnearbydangerandharsh,raspingnoiseswhenthebirdsarehaving

disputeswithothermalesofthesamespecies.

Zoologistsareveryinterestedinhowmalewhite-crownedsparrowscometolearntheirsongs

andcalls.Experimentsconductedindicatedthatthevocalizationsareofaninstinctivenature

engrainedinthebirdsfrombirth.However,thestudiesalsoshowedthatthechicksneeda

teacher—anadultmale—toassisttheminproperlylearningthesongsandcalls.Inone

experiment,zoologiststookamalesparrowchickeightdaysoldandisolatedhimfromallothers

ofhisspecies.Thebirdproducedsongsandcalls,buttheywereabnormalincomparisontothose

chicksraisedtogetherwithothersofthesamespecies.Inthesamesetofexperiments,another

malechickwasraisedwithanadultmale,and,overtime,thechickseemedtopickupthecorrect

vocalizationsbylisteningtotheadultmale.Thechickbeganlearningwithwhatthezoologists

calledsubsongs,whichwereweakerversionsoftheadult'ssongs.Overtime,thesubsongs

becamemoresimilartotheadult'ssongsandeventuallymatchedthemperfectly.

Thestudiesfurtherreinforcedwhatzoologistsalreadyknewaboutothersongbirds:Theyhave

ashortwindowinwhichtolearntheirsongsandcalls.?Thesparrowshadtolearnthemina

windowranginganywherefromfifteentofiftydaysafterhatching.?Afterfiftydays,malescould

notlearnproperlyeveniftheywereplacedwithadultmalesoftheirspecies.?ltissuspectedthat

mostmalechicksinthewildlearnthesongsandcallsdirectlyfromtheirfatherssinceadult

white-crownedsparrowsformstrongpairbonds.?Thisresultsinthemalesspendingalotoftime

withtheirchicksaftertheyhatchsincetheadultmalesdefendthenestandhelptheadult

femalesfeedthechicks.

Adiscoveryofevengreaterinterestfromthestudieswasthatwhite-crownedsparrowsfrom

thesameregionshavedistinctivedialectsintheirvocalizations.Forexample,inastudy

performedonthreedifferentgroupsinthreeseparateregionsinCalifornia,zoologistslearned

thattherewasadifferenceinthesongsfromeachregionaswellasdistinctivepatternsinthe

songsofmostofthesparrowsineacharea.Themaintheoryonwhythisoccursisthatmale

chickslearnthesongsfromtheirfathersand,inlateryears,becomeadultsandthenreturntothe

samebreedingandnestinggrounds.Theythereforepassonthesongstheylearnedtothenext

generation,soregionaldistinctionsinvocalizationsdevelopamongthesparrowsinparticular

places.

*Glossary

plumage:theentirecollectionoffeathersonabird

trilling:havingasingingsoundthatalternatestonesrapidly

hatch:tobebornbycomingoutofanegg

第38题

Accordingtoparagraph1,zoologistsstudiedthewhite-crownedsparrowinorderto

A.understandwhythebirdlivesincertaingeographicalareas

B.learnaboutsomeofthevocalizationsthatthebirdmakes

C.determinewhyitssongsandcallssounddifferentfromthoseofotherbirds

D.findoutmoreaboutthebird'suniquematinghabits

第39题

Thewordpiercinginthepassageisclosestinmeaningto

A.captivating

B.bothersome

C.shrill

0.repetitive

第40题

Inparagraph2,theauthor'sdescriptionofthesongsofthewhite-crownedsparrowmentionsall

ofthefollowingEXCEPT:

A.theamountoftimethateachofitssongstypicallylasts

B.thelengthofthepausebetweeneachsongthatitmakes

C.thefirstsoundthebirdmakeswhenitstartstosing

D.thenumberofdifferentsongsthatthebirdsings

第41题

Accordingtoparagraph2,whichofthefollowingistrueofthewhite-crownedsparrow'scalls?

A.Malessometimesmakethemwhentheyarefightingwithothermalesoftheirspecies.

B.Theyaremadeonlyingroupsinthesamewaythatthebirdsingsitssongs.

C.Thebirdmakesthemformanyreasons,butmatingcallsaremadethemostfrequently.

D.Atypicalwhite-crownedsparrowiscapableofmakingfewercallsthansongs.

第42题

Thewordengrainedinthepassageisclosestinmeaningto

A.fixed

B.revealed

C.improved

□.produced

第43题

Theauthordiscussessubsongsinparagraph3inorderto

A.describethemannerinwhichchickslearntosingsongsfromadultmalesparrows

B.differentiatebetweenthesongschickscansingandthesongsthatadultmalescansing

C.statethatchickswithnomaleinfluencecanonlylearnsubsongsratherthanregularones

D.pointoutthattheylackthepropervocalizationsrequiredsinceonlychickssingthem

第44题

Thewordtheminthepassagerefersto

A.thezoologists

B.weakerversions

C.thesubsongs

D.theadult'ssongs

第45题

Inparagraph3,theauthor'sdescriptionoftheexperimentscarriedoutonthewhite-crowned

sparrowmentionswhichofthefollowing?

A.Thenumberofexperimentsthatwereconductedbythezoologists

B.Theresultsofkeepingamalechickawayfromothermalesparrows

C.Theaverageamountoftimeittookmalechickstolearneachsongproperly

D.Thewaythatsomezoologistswereabletoteachadultmalesnewsongs

第46题

Thewordreinforcedinthepassageisclosestinmeaningto

A.defended

B.approved

C.armored

0.strengthened

第47题

Inparagraph4,theauthorimpliesthatthewhite-crownedsparrow

A.iscapableoflearningmultiplesongsandcallsinthefirsttwoweeksafterithatch