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目录

阅读篇章练习2

天文类2

地理地质类13

生物类25

生态学类34

古生物类42

人文社会科学类52

美国历史题材59

文学艺术类89

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天文类

Passage1

Notwocometseverlookidentical,buttheyhavebasicfeaturesincommon,oneofthemost

obviousofwhichisacoma.Acomalookslikeamisty,patchoflightwithoneormoretailsoften

streamingfromitinthedirectionawayfromtheSun.

Attheheartofacomet's

comaliesanucleusofsolid

material,typicallynomore

than10kilometersacross.The

visiblecomaisahugecloud

ofgasanddustthathas

escapedfromthenucleus,

whichitthensurroundslikean

extendedatmosphere.The

comacanextendasfarasa

millionkilometersoutward

fromthenucleus.Aroundthe

comathereisoftenaneven

largerinvisibleenvelopeofhydrogengas.

Themostgraphicproofthatthegrandspectacleofacometdevelopsfromarelativelysmall

andinconspicuouschunkoficeanddustwastheclose-upimageobtainedin1986bythe

EuropeanGiottoprobeofthenucleusofHalley'sComet.Itturnedouttobeabitlikeaverydark

asteroid,measuring16by8kilometers.Iceshaveevaporatedfromitsouterlayerstoleaveacrust

ofnearlyblackdustalloverthesurface.Brightjetsofgasfromevaporatingiceburstoutonthe

sidefacingtheSun,wherethesurfacegetsheatedup,carryingdustwiththem.Thisishowthe

comaandthetailsarecreated.

Cometsgrowtailsonlywhentheygetwarmenoughforiceanddusttoboiloff.Asacomet's

orbitbringsitclosertotheSun,firstthecomagrows,thentwodistincttailsusuallyform.One,

thelesscommonkind,containselectricallycharged(i.e.,ionized)atomsofgas,whichareblown

offdirectlyinthedirectionawayfromtheSunbythemagneticfieldofthesolarwind.Theother

tailismadeofneutraldustparticles,whichgetgentlypushedbackbythepressureofthesunlight

itself.Unliketheiontail,whichisstraight,thedusttailbecomescurvedastheparticlesfollow

theirownorbitsaroundtheSun.

1.Thepassagefocusesoncometsprimarilyintermsoftheir

(A)orbitalpattems

(B)comaandtails

(C)brightness

(D)size

2.Theword"identical”isclosestinmeaningto

(A)equallyfast

(B)exactlyalike

(C)neareachother

(D)invisible

3.Theword"heart"isclosestinmeaningto

(A)center

(B)edge

(C)tail

(D)beginning

4.WhydoestheauthormentiontheGiottoprobeinparagraph3?

(A)Ithadarelativelysmallandinconspicuousnucleus.

(B)Itwasverysimilartoanasteroid.

(C)Itwascoveredwithanunusualblackdust.

(D)Itprovidedvisualevidenceofthemakeupofacomet'snucleus.

5.Accordingtoparagraph3,itcanbeinferredfromthepassagethatthenucleusofacometis

madeupof

(A)dustandgas

(B)iceanddust

(C)hydrogengas

(D)electricallychargedatoms

6.Theword"graphic'1isclosestinmeaningto

(A)mathematical

(B)popular

(C)unusual

(D)vivid

7.Accordingtoparagraph3,whichofthefollowingoccurredastheicesfromHalley'sComet

evaporated?

(A)Blackdustwasleftonthecomet'ssurface.

(B)Thenucleusofthecometexpanded.

(C)Thetailofthecometstraightenedout.

(D)Jetsofgascausedthecomettoincreaseitsspeed.

8.Accordingtoparagraph4,allofthefollowingstatementsaboutthetailsofcometsaretrue

EXCEPT:

(A)Theycancontainelectricallychargedorneutralparticles.

(B)Theycanbeformedonlywhenthereissufficientheat.

(C)Theyareformedbeforethecomaexpands.

(D)TheyalwayspointinthedirectionawayfromtheSun.

9.Theword"distinct"isclosestinmeaningto

(A)visible

(B)gaseous

(C)separate

(D)new

10.Accordingtoparagraph4,comparedtothetailofelectricallychargedatoms,thetailof

neutraldustparticlesis

relatively

(A)long

(B)curved

(C)unpredictable

(D)bright

Passage2

Thelargestofthegiantgasplanets,Jupiter,withavolume1,300timesgreaterthanEarth's,

containsmorethantwicethemassofalltheotherplanetscombined.Itisthoughttobeagaseous

andfluidplanetwithoutsolidsurfaces.Haditbeensomewhatmoremassive,Jupitermighthave

attainedinternaltemperaturesashighastheignitionpointfornuclearreactions,anditwouldhave

flamedasastarinitsownright.Jupiterandtheothergiantplanetsareofalow-densitytypequite

distinctfromtheterrestrialplanets:theyarecomposedprsdominaotlyofsuchsubstancesas

hydrogen,helium,ammonia,andmethane,unliketerrestrialplanets.MuchofJupiter'sinterior

mightbeintheformofliquid,metallichydrogen.Normally,hydrogenisagas,butunder

pressuresofmillionsofkilogramspersquarecentimeter,whichexistinthedeepinteriorof

Jupiter,thehydrogenatomsmightlocktogethertoformaliquidwiththepropertiesofametal.

SomescientistsbelievethattheinnermostcoreofJupitermightberocky,ormetalliclikethecore

ofEarth.

Jupiterrotatesveryfast,

onceevery9.8hours.Asaresult,

itsclouds,whicharecomposed

largelyoffrozenandliquid

ammonia,havebeenwhipped

intoalternatingdarkandbright

bandsthatcircletheplanetat

differentspeedsindifferent

latitudes.JupitefspuzzlingGreat

RedSpotchangessizeasit

hoversintheSouthern

Hemisphere.Scientistsspeculateitmightbeagigantichurricane,whichbecauseofitslargesize

(theEarthcouldeasilyfitinsideit),lastsforhundredsofyears.

JupitergivesofftwiceasmuchheatasitreceivesfromtheSun.Perhapsthisisprimevalheat

orheatgeneratedbythecontinuedgravitationalcontractionoftheplanet.Anotherstarlike

characteristicofJupiterisitssixteennaturalsatellites,which,likeaminiaturemodeloftheSolar

System,decreaseindensitywithdistance-fromrockymoonsclosetoJupitertoicymoons

fartheraway.IfJupiterwereabout70timesmoremassive,itwouldhavebecomeastar.Jupiteris

thebest-preservedsampleoftheearlysolarnebula,andwithitssatellites,mightcontainthemost

importantcluesabouttheoriginoftheSolarSystem.

1.Whatwouldbethebesttitleforthisarticle?

(A)JupitarandItsPlanets

(B)TheGiantPlanets

(C)NuclearReactioninJupitar

(D)TheOriginoftheSolarSystem

2.Theword"flamed"inparagraph1isclosestinmeaningto

(A)burned

(B)divided

(C)fallen

(D)grown

3.Theword“they"inparagraph1refersto

(A)nuclearreactions

(B)giantplanets

(C)terrestrial

(D)substances

4.Accordingtotheparagraph1,hydrogencanbecomeametallic-likeliquidwhenitis

(A)extremelyhot

(B)combinedwithhelium

(C)similartoatmospheres

(D)undergreatpressures

5.Accordingtotheparagraph1,somescientistsbelieveJupiterandEartharesimilarinthatthey

bothhave

(A)solidsurfaces

(B)similarmasses

(C)similaratmospheres

(D)metalliccores

6.Accordingtoparagraph2,thecloudssurroundingJupiteraremostlycomposedof

(A)ammonia

(B)helium

(C)hydrogen

(D)methane

7.Itcanbeinferredfromparagraph2thattheappearanceofalternatingbandscirclingJupiteris

causedby

(A)theGreatRedSpot

(B)heatfromtheSun

(C)theplanetsfastrotation

(D)Stormsfromtheplanet'sSouthernHemisphere

8.Theauthorusestheword“puzzling"inparagraph2tosuggestthattheGreatRedSpotis

(A)theonlyspotofitskind

(B)notwellunderstood

(C)amongthelargestofsuchspots

(D)aproblemfortheplanet'scontinuedexistence

9.Paragraph3supportswhichofthefollowingconclusions?

(A)JupitergivesofftwiceasmuchheatastheSun.

(B)Jupiterhasaweakergravitationalforcethantheotherplanets.

(C)ScientistsbelievethatJupiterwasonceastar.

(D)ScientistsmightlearnaboutthebeginningoftheSolarSystembyStudyingJupiter.

10.Whydoestheauthormentionprimevalheatinparagraph3?

(A)ToprovideevidencethatJupiterisolderthantheSun

(B)ToprovideevidencethatJupiterisolderthantheotherplanets

(C)TosuggestapossibleexplanationforthenumberofsatellitesthatJupiterhas

(D)TosuggestapossiblesourceofthequantityofheatthatJupitergivesoff

11.Accordingtotheparagraph3,Jupiter'smostdistantmoonis

(A)theleastdense

(B)thelargest

(C)warmonthesurface

(D)veryrockyonthesurface

Practice:Pleasematchthedefinitionontherighttothecorrectwordontheleft

.A.ignitionleadingorsuperior

predominantachieveorarrive

attaintoremainsuspendedoveraplaceorobject

interiorfiringandlighting

hoverinner

B.speculatethinkorguess

giganticgiant

primevalancient

contractionforcingtogether

miniaturesmall

TheMoon,whichhasundergoneadistinctandcomplex

geologicalhistory,presentsastrikingappearance.Themoon

maybedividedintotwomajorterrains:theMaria(dark

lowlands)andtheTerrace(brighthighlands).Thecontrastinthe

reflectivity(thecapabilityofreflectinglight)ofthesetwo

terrainssuggestedtomanyearlyobserversthatthetwoterrains

mighthavedifferentcompositions,andthissuDpositionwas

confirmedbymissionstotheMoonsuchasSurveyorand

Apollo.Oneofthemostobviousdifferencesbetweenthe

terrainsisthesmoothnessoftheMariaincontrasttothe

roughnessofthehighlands.Thisroughnessismostlycausedby

theabundanceofcraters:thehighlandsarecompletelycovered

bylargecraters,whilethecratersoftheMariatendtobemuchsmaller.Itisnowknownthatthe

vastmajorityoftheMoon'scraterswereformedbytheimpactofsolidbodieswiththelunar

surface.

MostofthenearsideoftheMoonwasthoroughlymappedandstudiedfromtelescopic

picturesyearsbeforetheageofspaceexploration.Earth-basedtelescopescanresolveobjectsas

smallasafewhundredmetersonthelunarsurface.Closeobservationofcraters,combinedwith

thewaytheMoondiffuselyreflectssunlight,ledtotheunderstandingthattheMooniscoveredby

asurfacelayer,orregolith,thatoverliesthesolidrockoftheMoon.Telescopicimagespermitted

thecatalogingofabewilderingarrayoflandforms.Craterswerestudiedforcluestotheirorigin;

thelargewispymarkswereseen.Strange,sinuousfeatureswereobservedintheMaria.Although

variouslandformswerecatalogued,themajorityofastronomers*attentionwasfixedoncraters

andtheirorigins.

Astronomershaveknownforafairlylongtimethattheshapeofcraterschangesasthey

increaseinsize.Smallcraterswithdiametersoflessthan10-15kmhaverelativelysimpleshapes.

Theyhaverimcreststhatareelevatedabovethesunoundingterrain,smooth,bowl-shaped

interiors,anddepthsthatareaboutone-sixththeirdiameters.Thecomplexityofshapeincreases

forlargercraters.

1.Whatdoesthepassagemainlydiscuss?

(A)WhatastronomerslearnedfromtheSurveyorandApollospacemissions.

(B)CharacteristicsofthemajorterrainsoftheMoon.

(C)TheoriginoftheMoon'scraters.

(D)TechniquesusedtocataloguetheMoon*slandforms.

2.Theword"undergone"inparagraph1isclosestinmeaningto

(A)altered

(B)substituted

(C)experienced

(D)preserved

3.Accordingtoparagraph1,theMariadifferfromtheTerracemainlyintermsof

(A)age

(B)mannerofcreation

(C)size

(D)composition

4.ThepassagesupportswhichofthefollowingstatementsabouttheSurveyorandApollo

missions?

(A)TheyconfirmedearliertheoriesabouttheMoon'ssurface.

(B)TheyrevealedthatpreviousideasabouttheMoon'scraterswereincorrect.

(C)TheywereunabletoprovidedetailedinfonnationabouttheMoon'ssurface.

(D)TheywereunabletoidentifyhowtheMoon'scratersweremade.

5.Theword"vast"inparagraph1isclosestinmeaningto

(A)special

(B)known

(C)varied

(D)great

6.AllofthefollowingaretrueoftheMariaEXCEPT:

(A)Theyhavesmallcraters.

(B)Theyhavebeenanalyzedbyastronomers.

(C)Theyhavearoughtexture.

(D)Theytendtobedarkerthantheterrace.

9.Accordingtotheparagraph2,lunarresearchershavefocusedmostlyon

(A)thepossibilityoffindingwaterontheMoon

(B)thelunarregolith

(C)catalogingvariouslandformations

(D)cratersandtheirorigins

Passage4

InJulyof1994,anastoundingseriesofeventstookplace.Theworldanxiouslywatchedas,

everyfewhours,ahurtlingchunkofcometplungedintotheatmosphereofJupiter.Allofthe

twenty-oddfragments,collectivelycalledcometShoemaker-Levy9afteritsdiscoverers,were

oncepartofthesameobject,nowdismemberedandstrungoutalongthesameorbit.This

cometarytrain,glisteninglikeastringofpearls,hadbeenfirstglimpsedonlyafewmonthsbefore

itsfatefulimpactwithJupiter,andratherquicklyscientistshadpredictedthatthefragmentswere

onacollisioncoursewiththegiantplanet.

Theimpactcausedan

explosionclearlyvisible

fromEarth,abright

flamingfirethatquickly

expandedaseachicymass

incinerateditself.When

eachfragmentslammedat

60kilometerspersecond

intothedenseatmosphere,

itsimmensekineticenergy

wastransformedintoheat,producingasuperheatedfireballthatwasejectedbackthroughthe

tunnelthefragmenthadmadeafewsecondsearlier.Theresiduesfromtheseexplosionslefthuge

blackmarksonthefaceofJupiter,someofwhichhavestretchedouttoformdarkribbons.

Althoughthisimpacteventwasofconsiderablescientificimport,itespeciallypiquedpublic

curiosityandinterest.Photographsofeachcollisionmadetheeveningtelevisionnewscastand

werepostedontheInternet.Thiswaspossiblythemostopenscientificendeavorinhistory.The

faceofthelargestplanetinthesolarsystemwaschangedbeforeourveryeyes.Andforthevery

firsttime,mostofhumanitycametofullyappreciatethefactthatweourselvesliveonasimilar

target,aworldsubjecttocatastrophebyrandomassaultsfromcelestialbodies.Thatrealization

wasasurprisetomany,butitshouldnothavebeen.Oneofthegreattruthsrevealedbythelast

fewdecadesofplanetaryexplorationisthatcollisionsbetweenbodiesofallsizesarerelatively

commonplace,atleastingeologicterms,andwereevenmorefrequentintheearlysolarsystem.

1.Paragraph1mentionswhichofthefollowingwithrespecttothefragmentsofcomet

Shoemaker-Levy9?

(A)Theywereoncecombineinalargerbody.

(B)SomeofthemburnedupbeforeenteringtheatmosphereofJupiter.

(C)SomeofthemarestillorbitingJupiter.

(D)Theyhaveanunusualorbit.

2.Theword"collectively"isclosestinmeaningto

(A)respectively

(B)popularly

(C)also

(D)together

3.Accordingtoparagraph1,theauthorcomparesthefragmentsofcometShoemaker-Levy9toall

ofthefollowingEXCEPT

(A)adismemberedbody

(B)atrain

(C)apearlnecklace

(D)agiantplanet

4.Accordingtoparagraph1,beforecometShoemaker-Levy9hitJupiterinJuly1994,scientists

(A)hadbeenunawareofitsexistence

(B)hadbeentrackingitforonlyafewmonths

(C)hadobserveditsbreakupintotwenty-oddfragments

(D)haddecideditwouldnotcollidewiththeplanet

5.BeforethecometfragmentsenteredtheatmosphereofJupiter,theyweremostlikely

(A)invisible

(B)black

(C)frozen

(D)exploding

6.Thephrase"incinerateditselfisclosestinmeaningto

(A)burnedup

(B)brokeintosmallerpieces

(C)increaseditsspeed

(D)grewinsize

7.Accordingtoparagraph2,whichofthefollowingismentionedasevidenceoftheexplosions

thatisstillvisibleonJupiter?

(A)fireballs

(B)icemasses

(C)blackmarks

(D)tunnels

8.Paragraph3discussestheimpactofthecometShoemaker-Levy9primarilyintermsof

(A)itsimportanceasaneventofgreatscientificsignificance

(B)itseffectonpublicawarenessofthepossibilityofdamagetoEarth

(C)thechangesitmadetothesurfaceofJupiter

(D)theeffectithadontelevisionbroadcasting

9.The“target“mostprobablyreferredto

(A)Earth

(B)Jupiter

(C)thesolarsystem

(D)acomet

地理地质类

Passage5

Themineralparticlesfoundinsoilrangeinsizefrommicroscopicclayparticlestolarge

boulders.Themostabundantparticles—sand,silt,andclay—arethefocusofexaminationin

studiesofsoiltexture.Textureisthetermusedtodescribethecompositesizesofparticlesinasoil

sample,typicallyseveralrepresentativehandfuls.

Tomeasuresoiltexture,thesand,silt,andclayparticlesaresortedoutbysizeandweight.

Theweightsofeachsizearethenexpressedasapercentageofthesampleweight.Inthefield,soil

texturecanbeestimatedbyextractingahandfulofsoilandsqueezingthedampsoilintothree

basicshapes;(1)cast,alumpformedbysqueezingasampleinaclenchedfist;(2)thread,apencil

shapeformedbyrollingsoilbetweenthepalms;and(3)ribbon,aflatfishshapeformedby

squeezingasmallsamplebetweenthethumbandindexfinger.Thebehavioralcharacteristicsof

thesoilwhenmoldedintoeachoftheseshapes,iftheycanbeformedatall,providethebasisfora

generaltexturalclassification.Thebehaviorofthesoilinthehandtestisdeterminedbythe

amountofclayinthesample.Clayparticlesarehighlycohesive,andwhendampened,behaveasa

plastic.Thereforethehighertheclaycontentinasample,themorerefinedanddurabletheshapes

intowhichitcanbemolded.

Anothermethodofdeterminingsoiltextureinvolvestheuseofdevicescalledsediment

sieves,screensbuiltwithaspecifiedmeshsize.Whenthesoilisfilteredthroughagroupofsieves,

eachwithadifferentmeshsize,theparticlesbecomegroupedincorrespondingsizecategories.

Eachcategorycanbeweighedtomakeatexturaldetermination.Althoughsievesworkwellforsilt,

sand,andlargerparticles,theyarenotSDDropriateforclayparticles.Clayisfartoosmalltosieve

accurately;therefore,insoilswithahighproportionofclay,thefineparticlesaremeasuredonthe

basisoftheirsettlingvelocitywhensuspendedinwater.Sinceclayssettlesoslowly,theyare

easilysegregatedfromsandandsilt.Thewatercanbedrawnoffandevaporated,leavingaresidue

ofclay,whichcanbeweighed.

1.Whatdoesthepassagemainlydiscuss?

(A)Characteristicsofhighqualitysoil

(B)Particlestypicallyfoundinmostsoils

(C)Howahighclaycontentaffectsthetextureofsoil

(D)Waystodeterminethetextureofsoil

2.Thephrase"sortedout"isclosestinmeaningto

(A)mixed

(B)replaced

(C)carried

(D)separated

3.Itcanbeinferredthatthenamesofthethreebasicshapesmentionedinparagraph2reflect

(A)thewaythesoilisextracted

(B)theresultsofsqueezingthesoil

(C)theneedtocheckmorethanonehandful

(D)thedifficultyofformingdifferentshapes

4.Theword“dampened"isclosestinmeaningto

(A)damaged

(B)stretched

(C)moistened

(D)examined

5.Accordingtoparagraph2,whichofthefollowingcanbeinferredfromthepassageaboutasoil

samplewithlittleornoclayinit?

(A)Itisnotveryheavy.

(B)Itmaynotholditsshapewhenmolded.

(C)Itssh叩eisdurable

(D)Itstexturecannotbeclassified

6.Theword"hey"refersto

(A)categories

(B)sieves

(C)largerparticles

(D)clayparticles

7.Itcanbeinfenedfromthepassagethatthesedimentsievehasanadvantageoverthehandtest

indeterminingsoiltexturebecause

(A)usingthesievetakeslesstime

(B)thesievecanmeasureclay

(C)lesstrainingisrequiredtousethesieve

(D)thesieveallowsforamoreexactmeasure

8.Duringtheproceduredescribedinparagraph3,whenclayparticlesareplacedintowaterthey

(A)sticktothesidesofthewatercontainer

(B)takesometimetosinktothebottom

(C)separateintodifferentsizes

(D)dissolvequickly

9.Theword"fine"isclosestinmeaningto

(A)tiny

(B)many

(C)excellent

(D)various

Passage6

In1972,acenturyafterthefirstnationalparkintheUnitedStateswasestablishedat

Yellowstone,legislationwas

passedtocreatetheNationalOLYMPICCOAST.(THUNOCRBAY

MarineSanctuariesProgram.CORDQXBAKISniiwAGeN

TheintentofthislegislationMONITOR

wastoprovideprotectiontoMCNTEREYBAY

CHANHELISLANDS

selectedcoastalhabitatssimilarFLOWDA

PARMUMUMOKUAKEA

■MXMNMHMMMMUNEWT

tothatexistingforlandareasFLOWERGAADEN

BANKS

designatedasnationalparks.HMAIIAMISLANDS/

HUMPWCKWHALE

Thedesignationofanarea*sFAGATHIBAY

AMERICANSAMOA(U.S.)

marinesanctuaryindicatesthat

itisaprotectedarea,justasa

nationalparkis.Peoplearepermittedtovisitandobservethere,butlivingorganismsandtheir

environmentsmaynotbeharmedorremoved.

TheNationalMarineSanctuariesProgramisadministeredbytheNationalOceanicand

AtmosphericAdministration,abranchoftheUnitedStatesDepartmentofCommerce.Initially,70

siteswereproposedascandidatesforsanctuarystatus.Twoandahalfdecadeslater,onlyfifteen

sanctuarieshadbeendesignated,withhalfoftheseestablishedafter1978.Theyrangeinsizefrom

theverysmall(lessthan1squarekilometer)FagateleBayNationalMarineSanctuaryinAmerican

SamoatotheMontereyBayNationalMarineSanctuaryinCalifornia,extendingover15,744

squarekilometers.

TheNationalMarineSanctuariesProgramisacrucialpartofnewmanagementpracticesin

whichwholecommunitiesofspecies,andnotjustindividualspecies,areofferedsomedegreeof

protectionfromhabitatdegradationandoverexploitation.Onlyinthiswaycanareasonable

degreeofmarinespeciesdiversitybemaintainedinasettingthatalsomaintainsthenatural

interrelationshipsthatexistamongthesespecies.

SeveralothertypesofmarineprotectedareasexistintheUnitedStatesandothercountries.

TheNationalEstuarineResearchReserveSystem,managedbytheUnitedStatesgovernment,

includes23designatedandprotectedestuaries.OutsidetheUnitedStates,marineprotected-area

programsexistasmarineparks,reserves,andpreserves.Over100designatedareasexistaround

theperipheryoftheCaribbeanSea.Othersrangefromthewell-knownAustralianGreatBamer

ReefMarineParktolesser-knownparksincountriessuchasThailandandIndonesia,where

tourismisplacinggrowingpressuresonfragilecoralreefsystems.Asstate,national,and

internationalagenciescometorecognizetheimportanceofconservingmarinebiodiversity,

marineprotectedareas,whetherassanctuaries,parks,orestuarinereserves,willplayan

increasinglyimportantroleinpreservingthatdiversity.

1.Whatdoesthepassagemainlydiscuss?

(A)Differencesamongmarineparks,sanctuaries,andreserves

(B)Variousmarineconservationprograms

(C)Internationalagreementsoncoastalprotection

(D)Similaritiesbetweenlandandseaprotectedenvironments

2.Theword"intent"isclosestinmeaningto

(A)repetition

(B)approval

(C)goal

(D)revision

3.Theword“administered“isclosestinmeaningto

(A)managed

(B)recognized

(C)opposed

(D)justified

4.Theword"these'1refersto

(A)sites

(B)candidates

(C)decades

(D)sanctuaries

5.ThepassagementionstheMontereyBayNationalMarineSanctuaryasanexampleofa

sanctuarythat

(A)isnotwellknow

(B)coversalargearea

(C)issmallerthantheFagateleBayNationalMarineSanctuary

(D)wasnotoriginallyproposedforsanctuarystatus

6.Accordingtotheparagraph1,whenwastheNationalMarineSanctuariesProgramestablished?

(A)before1972

(B)after1987

(C)onehundredyearsbeforenationalparkswereestablished

(D)onehundredyearsafterYellowstoneNationalParkwasestablished

7.Theword"periphery"isclosestinmeaningto

(A)depth

(B)landmass

(C)warmhabitat

(D)outeredge

8.ThepassagementionswhichofthefollowingasathreattomarineareasoutsidetheUnited

States?

(A)limitationsinfinancialsupport

(B)theuseofmarinespeciesasfood

(C)variabilityoftheclimate

(D)increasesintourism

Passage7

Glaciersarelargemassesoficeon

landthatshowevidenceofpastorpresent

movement.Theygrowbythegradual

transformationofsnowintoglacierice.

Afreshsnowfallisafluffymassof

looselypackedsnowflakes,smalldelicate

icecrystalsgrownintheatmosphere.Asthe

snowagesonthegroundforweeksor

months,thecrystalsshrinkandbecome

morecompact,andthewholemassbecomes

squeezedtogetherintoamoredenseform,

granularsnow.Asnewsnowfallsand

buriestheoldersnow,thelayersofgranular

snowfurthercompacttoformfirm,amuchdenserkindofsnow,usuallyayearormoreold,which

haslittleporespace.Furtherburialandslowcementationfinallyproducesolidglacialice.Inthis

process,thegrowthofnewcrystalsattheexpenseofoldones,thepercentageofairisreduced

fromabout90percentforsnowflakestolessthan20percentforglacierice.Thewholeprocess

maytakeaslittleasafewyears,butmorelikelytenortwentyyearsorlonger.Thesnowisusually

manymetersdeepbythetimethelowerlayersareconvertedintoice.

IncoldglaciersthoseformedinthecoldestregionsoftheEarth,theentiremassoficeisat

temperaturesbelowthemeltingpointandnofreewaterexists.Inlempcraleglaciers,theiceisat

themeltingpointateverypressurelevelwithintheglacier,andfreewaterispresentassmalldrops

oraslargeraccumulationsintunnelswithinorbenea