冲分高级班阅读TPO分册（适合89-100分）

冲分高级班阅读TP0分册

（适合89-100分）

TP0414

NavajoArt4

ClimateofVenus10

TradeandEarlyStateFormation16

TPO4223

GeographicIsolationofSpecies23

ExplainingDinosaurExtinction30

CallistoandGanymede36

TPO4340

TheEmpireofAlexandertheGreat40

TheOriginofPetroleum46

ElNino51

TPO4458

FromFishtoTerrestrialVertebrates58

TheUseoftheCameraObscura65

Seagrasses71

TPO4577

TheBeringiaLandscape77

WindPollination83

FeedingStrategiesintheOcean88

TPO4693

TheOriginsofWriting93

TheCommercialRevolutioninMedievalEurope99

EcosystemDiversityandStability105

TPO47111

RomanCulturalInfluenceonBritain111

TermiteIngenuity116

CoralReefs121

TPO48126

ChinesePopulationGrowth126

DeterminingDinosaurDiet132

ClimateandUrbanDevelopment138

TPO49144

AncientCoastlines144

MovableType150

BackgroundfortheIndustrialRevolution156

TPO50162

AmericanRailroads162

TheAchievementofBrazilianIndependence168

StarDeath174

XPO-5179

AttemptsatDeterminingEarth'sAge179

WaterSupplyinVenice185

TheEarlyHistoryofMotionPictures192

XPO-6199

TheOriginsofWriting199

SoilFertilization206

TheCollapseoftheMaya213

XPO-7220

UrbanDevelopmentintheUnitedStatesinthe19thCentury220

TheClimateofJapan227

EconomicDeclineinEuropeduringthe14thCentury234

XPO-8241

EarlyTheoriesofContinentalDrift241

BioluminescenceinMarineCreatures248

BirdColonies255

XPO-9262

ArtisansinSixteenth-CenturyEurope262

DiseaseandHistory267

Earth'sAtmosphere272

KEY277

TPO41

NavajoArt

TheNavajo,aNativeAmericanpeoplelivinginthesouthwesternUnitedStates,

liveinsmallscatteredsettlements.Inmanyrespects,suchaseducation,occupation,

andleisureactivities,theirlifeislikethatofothergroupsthatcontributetothe

diversesocialfabricofNorthAmericancultureinthetwenty-firstcentury.Atthesame

time,theyhaveretainedsometraditionalculturalpracticesthatareassociatedwith

particularartforms.Forexample,themostimportanttraditionalNavajorituals

includetheproductionoflargefloorpaintings.Theseareactuallymadebypouring

thin,finelycontrolledst-eamsofcoloredsandsorpulverizedvegetableandmineral

substances,pollen,andflowersinprecisepatternsontheground.Thelargestof

thesepaintingsmaybeupto5.5metersindiameterandcovertheentirefloorofa

room.Workingfromtheinsideofthedesignoutward,theNavajoartistandhis

assistantswillsifttheblack,white,bluish-gray,orange,andredmaterialsthrough

theirfingerstocreatethefinelydetailedimagery.Thepaintingsandchantsusedin

theceremoniesaredirectedbywell-trainedartistsandsingerswhoenlisttheaidof

spiritswhoareimpersonatedbymaskedperformers.Thetwenty-fourknownNavajo

chantscanberepresentedbyupto500sandpaintings.Thesecomplexpaintings

serveasmemoryaidstoguidethesingersduringtheperformanceoftheritualsongs,

whichcanlastuptoninedays.

Thepurposeandrreaningofthesandpaintingscanbeexplainedbyexamining

oneofthemostbasicidealsofNavajosociety,embodiedintheirwordhozho(beauty

orharmony,goodness,andhappiness).Itcoexistswithhochxo("ugliness,"or"evil,"

and"disorder")inaworldwhereopposingforcesofdynamismandstabilitycreate

constantchange.Whentheworld,whichwascreatedinbeauty,becomesuglyand

disorderly,theNavajogathertoperformritualswithsongsandmakesandpaintings

torestorebeautyandharmonytotheworld.Someillnessisitselfregardedasatype

ofdisharmony.Thus,therestorationofharmonythroughaceremonycanbepartofa

curingprocess.

Menmakesandpaintingsthatareaccuratecopiesofpaintingsfromthepast.

Thesongssungoverthepaintingsarealsofaithfulrenditionsofsongsfromthepast.

Byrecreatingthesearts,whichreflecttheoriginalbeautyofcreation,theNavajo

bringbeautytothepresentworld.AsrelativenewcomerstotheSouthwest,aplace

wheretheirclimate,neighbors,andrulerscouldbeequallyinhospitable,theNavajo

createdtheseartformstoaffecttheworldaroundthem,notjustthroughthe

recountingoftheactionssymbolized,butthroughthebeautyandharmonyofthe

artworksthemselves.Thepaintingsgenerallyillustrateideasandeventsfromthelife

ofamythicalhero,who,afterbeinghealedbythegods,gavegiftsofsongsand

paintings.Workingfrommemory,theartistsre-createthetraditionalformofthe

imageasaccuratelyaspossible.

TheNavajoarealsoworld-famousforthedesignsontheirwovenblankets.

Navajowomenownthefamilyflocks,controltheshearingofthesheep,thecarding,

thespinning,anddyingofthethread,andtheweavingofthefabrics.Whilethemen

whomakefaithfulcopiesofsandpaintingsfromthepastrepresenttheprincipleof

stabilityinNavajothought,womenembodydynamismandcreatenewdesignsfor

everyweavingtheymake.Weavingisaparadigmofthecreativityofamythic

ancestornamedSpiderWomanwhowovetheuniverseasacosmicwebthatunited

earthandsky.Itwasshewho,accordingtolegend,taughtNavajowomenhowto

weave.Astheypreparetheirmaterialsandweave.Navajowomenimitatethe

transformationsthatoriginallycreatedtheworld.Workingontheirlooms,Navajo

weaverscreateimagesthroughwhichtheyexperienceharmonywithnature.Its

theirmeansofcreatingbeautyandtherebycontributingtothebeauty,harmony,and

healingoftheworld.Thus,weavingisawayofseeingtheworldandbeingpartofit.

1.Theword,'precise,^isclosestinelaborateplanning.

meaningto[Paragraph1]

A.colorfulTheNavajo,aNativeAmerican

B.exactpeoplelivinginthesouthwestern

C.delicateUnitedStates,liveinsmallscattered

D.complexsettlements.Inmanyrespects,such

aseducation,occupation,andleisure

2.Theword"enlist"inthepassageisactivities,theirlifeislikethatofother

closestinmeaningtogroupsthatcontributetothediverse

A.assistsocialfabricofNorthAmericanculture

B.requireinthetwenty-firstcentury.Atthesame

C.describetime,theyhaveretainedsome

D.recruittraditionalculturalpracticesthatare

associatedwithparticularartforms.

3.WhatcanbeinferredfromForexample,themostImportant

paragraph1abouttheNavajoritualtraditionalNavajoritualsincludethe

chants?productionoflargefloorpaintings.

A.Thereisalargenumberofthem.Theseareactuallymadebypouring

B.Eachofthemcorrespondstoathin,finelycontrolledstreamsof

particularsandpainting.coloredsandsorpulverizedvegetable

C.Theyaredifficulttoremember.andrrineralsubstances,pollen,and

D.Theydonottakelongtoperformflowersinprecisepatternsonthe

ground.Thelargestofthesepaintings

4.Accordingtoparagraph1,allofthemaybeupto5.5metersindiameter

followingaretrueofmanyimportantandcovertheentirefloorofaroom.

NavajoritualsEXCEPT:Workingfromtheinsideofthedesign

A.Theyinvolvethecreationoflarge,outward,theNavajoartistandhis

detailedimages.assistantswillsifttheblack,white,

B.Theyincludeperformerswhosebluish-gray,orange,andredmaterials

facesarecovered.throughtheirfingerstocreatethe

C.Theytakeplaceindoors.finelydetailedimagery.Thepaintings

D.Theyareperformedwithoutandchantsusedintheceremoniesare

directedbywell-trainedartistsandthemeaninginimportantwaysor

singerswhoenlisttheaidofspiritsleaveoutessentialinformation

whoareimpersonatedbymasked

performers.Thetwenty-fourknown

Navajochantscanberepresentedby

upto500sandpaintings.These

complexpaintingsserveasmemory

aidstoguidethesingersduringthe

performanceoftheritualsongs,which

canlastuptoninedays.

5.Itcanbeinferredfromthe[Paragraph2]

discussionofillnessandcuringinThepurposeandmeaningofthe

paragraph2thatsandpaintingscanbeexplainedby

A.theNavajoconsiderillnesstoexaminingoneofthemostbasiciceals

alwayshaveasupernaturalcauseofNavajosociety,embodiedintheir

B.ritualsinvolvingsongsandsandwordhozho(beautyorharmony,

paintingsmaybeusedtotreatangoodress,andhappiness).Itcoexists

illnesswithhochxo("ugliness,*'or"evil,"and

C.whenaNavajoisiI,uglyand"disorder")inaworldwhereopposing

disorderlysandpaintingsaremadeforcesofdynamismandstability

D.afteraseriousillness,aNavajocreateconstantchange.Whenthe

willtakepartinacererronyworld,whichwascreatedinbeauty,

becomesuglyanddisorderly,the

Navajogathertoperformritualswith

songsandmakesandpaintingsto

restorebeautyandharmonytothe

world.Someillnessisitselfregarded

asatypeofdisharmony.Thus,the

restorationofharmonythrougha

cererronycanbepartofacuring

process.

6.Theword“faithful”inthepassageis[Paragraph3]

closestinmeaningtoMenmakesandpaintingsthatare

A.modernaccuratecopiesofpaintingsfromthe

B.accuratepast.Thesongssungoverthe

C.wonderfulpaintingsarealsofaithfulrenditionsof

D.simplifiedsongsfromthepast.Byrecreating

thesearts,whichreflecttheoriginal

7.Whichofthesentencesbelowbestbeautyofcreation,theNavajobring

expressestheessentialinformationinbeautytothepresentworld.As

thehighlightedsentenceintherelativenewcomerstotheSouthwest,

passage?Incorrectchoiceschangeaplacewheretheirclimate,neighbors,

andrulerscouldbeequally

inhospitable,theNavajocreatedthese

A.TheNavajousedthesymbolismartformstoaffecttheworldaround

andbeautyoftheirworksofarttothem,notjustthroughtherecounting

improvetheirlifeinanoftenoftheactionssymbolized,butthrough

inhospitableenvironment.thebeautyandharmonyofthe

B.TheideastheNavajoholdaboutartworksthemselves.Thepaintings

symbolismandbeautyweregenerallyillustrateideasandevents

influencedbytheirinhospitablefromthelifeofamythicalhero,who,

climate,neighbors,andrulers.afterbeinghealedbythegods,gave

C.Whentheyfirstarrivedinthegiftsofsongsandpaintings.Working

Southwest,theNavajoproducedfrommemory,theartistsre-createthe

symbolicartformsthatpromotedtraditionalformoftheimageas

harmony.accuratelyaspossible.

D.Intheirworksofart,theNavajo

emphasizedbeautyandharmonythat

canbefoundevenunderthemost

inhospitablecircumstances.

8.Accordingtoparagraph3,whichof

thefollowingisoftenthesubjectof

Navajosandpaintings?

A.ThelandscapeoftheSouthwest

B.TraditionalNavajopractices

C.Historicaleventsthatoccurredin

theSouthwest

D.TheIlvesofheroesintraditional

Navajostories

9.Paragraph4supportswhichofthe[Paragraph4]

followingstatementsaboutNavajoTheNavajoarealso

weaversandweaving?world-famousforthedesignsontheir

A.Navajowomenoverseeallwovenblankets.Navajowomenown

aspectsofwoolproductionandthefanilyflocks,controltheshearing

weaving.ofthesheep,thecarding,thespinning,

B.Thewoolusedforblanketscomesanddyingofthethread,andthe

fromdifferentsheepthandoestheweavingofthefabrics.Whilethemen

woolusedforotherpurposes.whomakefaithfulcopiesofsand

C.Navajoweavershaveusedsomepaintingsfromthepastrepresentthe

ofthesamedesignsforhundredsofprincipleofstabilityinNavajothought,

years.womenembodydynamismandcreate

D.Weavingisdoneprimarilyforusenewdesignsforeveryweavingthey

inrituals.make.Weavingisaparadigmofthe

creativityofamythicancestornamed

SpiderWomanwhowovetheuniverse

asacosmicwebthatunitedearthandsky.Itwasshewho,accordingto

10.Theword"ancestor"inthelegend,taughtNavajowomenhowto

passageisclosestinmeaningtoweave.Astheypreparetheirmaterials

A.relativefromanearliergenerationandweave.Navajowomenimitatethe

B.personwhoestablishedatransformationsthatoriginallycreated

particulartraditioninasocietytheworld.Workingontheirlooms,

C.herofromancienttimesNavajoweaverscreateimages

D.personwhooncemadeimportantthroughwhichtheyexperience

contributionstoasocialgrouporharmonywithnature.Itistheirmeans

cultureofcreatingbeautyandthereby

contributingtothebeauty,harmony,

11.Whydoestheauthordiscuss“aandhealingoftheworld.Thus,

mythicancestor”？weavingisawayofseeingtheworld

A.ToshowhowNavajoideasofandbeingpartofit.

weavinghavechangedovertime

B.ToexplainwhytheNavajo

principleofstabilityismoreclearly

representedintheirweavingsthanin

theirsandpaintings

C.Toemphasizetheroleofnaturally

occurringweavingmaterialsinthe

creativeweavingsoftheNavajo

D.Tohelpexplainthesignificanceof

weavinginNavajoculture

12.Accordingtoparagraph4,Navajo

weaversimitate

A.traditionalweavingpatterns

B.patternsusedinsandpaintings

C.theactivitiesthroughwhichthe

worldwascreated

D.imagesfromnature

13.Lookatthefoursquares[■]]thatindicatewherethefollowingsentencecouldbe

addedtothepassage.

Sincethispurposeislimitedtothecontextoftheritual,thepaintingsare

destroyedwhentheritualiscompleted.

TheNavajo,aNativeAmericanpeoplelivinginthesouthwesternUnitedStates,

liveinsmallscatteredsettlements.Inmanyrespects,suchaseducation,occupation,

andleisureactivities,theirlifeislikethatofothergroupsthatcontributetothe

diversesocialfabricofNorthAmericancultureinthetwenty-firstcentury.Atthesame

time,theyhaveretainedsometraditionalculturalpracticesthatareassociatedwith

particularartforms.Forexample,themostimportanttraditionalNavajorituals

includetheproductionoflargefloorpaintings.Theseareactuallymadebypouring

thin,finelycontrolledstreamsofcoloredsandsorpulverizedvegetableandmineral

substances,pollen,andflowersinprecisepatternsontheground.Thelargestof

thesepaintingsmaybeupto5.5metersindiameterandcovertheentirefloorofa

room.Workingfromtheinsideofthedesignoutward,theNavajoartistandhis

assistantswillsifttheblack,white,bluish-gray,orange,andredmaterialsthrough

theirfingerstocreatethefinelydetailedimagery.[■]Thepaintingsandchantsused

intheceremoniesaredirectedbywell-trainedartistsandsingerswhoenlisttheaidof

spiritswhoareimpersonatedbymaskedperformers.[■]Thetwenty-fourknown

Navajochantscanberepresentedbyupto500sandpaintings.[■]Thesecomplex

paintingsserveasmemoryaidstoguidethesingersduringtheperformanceofthe

ritualsongs,whichcanlastuptoninedays.[■]

14.[Directions]Anintroductorysentenceforabriefsummaryofthepassageis

providedbelow.CompletethesummarybyselectedTHREEanswerchoicesthat

expressthemostimportantideasinthepassage.Somesentencesdonotbelongin

thesummarybecausetheyexpressideasthatarenotpresentedinthepassageor

areminorideasinthepassage.Thisquestionisworth2points.

NavajoartisfundamentallyconnectedtoaspectsofNavajoritualandbelief.

A.Navajosandpaintingsareanexpressionofthecloserelationshipbetweennature

andthespiritualworldInNavajoculture

B.Sandpaintings,whichhelpparticipantsinritualsrecalltraditionalchants,arepart

ofceremoniesdesignedtorestorebeautyandharmony.

C.WhereasNavajosandpaintingsareassociatedwithmaledeities,Navajoweaving

involvesrepresentationsoffemalefiguressuchasSpiderWoman.

D.IndividualNavajosandpaintingstypicallyembodytheprinciplesofharmonyand

disorder.

E.Sandpaintings,whicharecreatedbyNavajomen,arefaithfulre-creationsof

earlierworksandassuchrepresenttheprincipleofstability。

F.InNavajoculture,weavingisafemaleartandisassociatedwithcreativityand

change.

ClimateofVenus

Earthhasabundantwaterinitsoceansbutverylittlecarbondioxideinits

relativelythinatmosphere.Bycontrast,Venusisverydryanditsthickatmosphereis

mostlycarbondioxide.TheoriginalatmospheresofbothVenusandEarthwere

derivedatleastinpartfromgasesspewedforth,oroutgassed,byvolcanoes.The

gasesthatemanatefrompresent-dayvolcanoesonEarth,suchasMountSaint

Helens,arepredominantlywatervapor,carbondioxide,andsulfurdioxide.These

gasesshouldthereforehavebeenimportantpartsoftheoriginalatmospheresofboth

VenusandEarth.Muchofthewateronbothplanetsisalsothoughttohavecome

fromimpactsfromcomets,icybodiesformedintheoutersolarsystem.

Infact,waterprobablyoncedominatedtheVenusianatmosphere.Venusand

Eartharesimilarinsizeandmass,soVenusianvolcanoesmaywellhaveoutgassed

asmuchwatervaporasonEarth,andbothplanetswouldhavehadaboutthesame

numberofcometsstriketheirsurfaces.Studiesofhowstarsevolvesuggestthatthe

earlySunwasonlyabout70percentasluminousasitisnow,sothetemperaturein

Venus*earlyatmospheremusthavebeenquiteabitlower.Thuswatervaporwould

havebeenabletoliquefyandformoceansonVenus.Butifwatervaporandcarbon

dioxidewereoncesocommonintheatmospheresofbothEarthandVenus,what

becameofEarth'scarbondioxide?AndwhathappenedtothewateronVenus?

Theanswertothefirstquestionisthatcarbondioxideisstillfoundinabundance

onEarth,butnow,insteadofbeingintheformofatmosphericcarbondioxide,itis

eitherdissolvedintheoceansorchemicallyboundintocarbonaterocks,suchasthe

limestoneandmarblethatformedintheoceans.IfEarthbecameashotasVerus,

muchofitscarbondioxidewouldbeboiledoutoftheoceansandbakedoutofthe

crust.Ourplanetwouldsoondevelopathick,oppressivecarbondioxideatmosphere

muchlikethatofVenus.

ToanswerthequestionaboutVenus*lackofwater,wemustreturntotheearly

historyoftheplanet.Justasonpresent-dayEarth,theoceansofVenuslimitedthe

amountofatmosphericcarbondioxidebydissolvingitintheoceansandbindingitup

incarbonaterocks.ButbeingclosertotheSunthanEarthis,enoughoftheliquid

wateronVenuswouldhavevaporizedtocreateathickcoverofwatervaporclouds.

Sincewatervaporisagreenhousegas,thishumidatmosphere—perhapsdenser

thanEarth'spresent-dayatmosphere,butfarlessdensethantheatmospherethat

envelopsVenustoday—wouldhaveefficientlytrappedheatfromtheSun.Atfirst.this

wouldhavehadlittleeffectontheoceansofVenus.Althoughthetemperaturewould

haveclimbedabove100°C,theboilingpointofwateratsealevelonEarth,the

addedatmosphericpressurefromwatervaporwouldhavekeptthewaterinVenus,

oceansintheliquidstale.

Thishotandhumidstateofaffairsmayhavepersistedforseveralhundred

millionyears.ButastheSun'senergyoutputslowlyincreasedovertime,the

temperatureatthesurfacewouldeventuallyhaverisenabove374℃.Abovethis

temperature,nomatterwhattheatmosphericpressure,Venus'oceanswouldhave

beguntoevaporate,andtheaddedwatervaporintheatmospherewouldhave

increasedthegreenhouseeffect.Thiswouldhavemadethetemperatureevenhigher

andcausedtheoceanstoevaporatefaster,producingmorewatervapor.That,inturn

wouldhavefurtherintensifiedthegreenhouseeffectandmadethetemperatureclimb

higherstill.

OnceVenus'oceansdisappeared,sodidthemechanismforremovingcarbon

dioxidefromtheatmosphere.Withnooceanstodissolveit,outgassedcarbon

dioxidebegantoaccurrulateintheatmosphere,intensifyingthegreenhouseeffect

evenmore.Temperatureseventuallybecamehighenoughtol,bakeout“anycarbon

dioxidethatwastrappedincarbonaterocks.Thisliberatedcarbondioxideformedthe

thickatmosphereofpresent-dayVenus.Overtime,therisingtemperatureswould

haveleveledoff,solarultravioletradiationhavingbrokendownatmosphericwater

vapormoleculesintohydrogenandoxygen.Withallthewatervaporgone,the

greenhouseeffectwouldnolongerhaveaccelerated.

[Paragraph1]

1.Accordingtoparagraph1,inwhatEarthhasabundantwaterints

majorrespectareVenusandEarthoceansbutverylittlecarbondioxidein

differentfromeachother?itsrelativelythinatmosphere.By

A.Whethercarbondioxidev/ascontrast,Venusisverydryandits

presentintheiroriginalatmospheresthickatmosphereismostlycarbon

B.Howthintheiroriginaldioxide.Theoriginalatmospheresof

atmosphereswerebothVenusandEarthwerederivedat

C.Whattheirpresent-dayleastinpartfromgasesspewedforth,

atmospheresmainlyconsistoforoutgassed,byvolcanoes.The

D.Howlongagotheyfirstgasesthatemanatefrompresent-day

developedanatmospherevolcanoesonEarth,suchasMount

SaintHelens,arepredominantlywater

2.Whydoestheauthormentionvapor,carbondioxide,andsulfur

"present-dayvolcanoesonEarth"?dioxide.Thesegasesshouldtherefore

A.Toprovideanexampleofanhavebeenimportantpartsofthe

importantdifferencebetweenoriginalatmospheresofbothVenus

present-dayVenusandpresent-dayandEarth.Muchofthewateronboth

Earthplanetsisalsothoughttohavecome

B.TohelpexplainwhyEarth'sfromimpactsfromcomets,icybodies

atmospherestillcontainstracesofformedintheoutersolarsystem.

sulfurdioxidebutVenus'doesnot

C.Toindicateonesourceof

informationaboutthelikely

compositionoftheoriginal

atmospheresofVenusandEarth

D.Toaccountforthefactthat

Earth'swatersupplynolongercomes

primarilyfromimpactingcomets

3.Accordingtoparagraph2,whatis[Paragraph2]

onereasonforthinkingthatatoneInfact,waterprobablyonce

time,thereweresignificantamountsofdominatedtheVenusianatmosphere.

wateronVenus?VenusandEartharesimilarinsize

A.BecauseofVenus'sizeandmass,andmass,soVenusianvolcanoesmay

itsvolcanoesprobablyproducedmuchwellhaveoutgassedasmuchwater

morewatervaporthanvolcanoesonvaporasonEarth,andbothplanets

Earthdid.wouldhavehadaboutthesame

B.ThelowtemperatureofVenus'numberofcometsstriketheirsurfaces.

earlyatmospherecanbeexplainedStudiesofhowstarsevolvesuggest

onlybythepresenceofwater.thattheearlySunwasonlyabout70

C.Thepresenceofcarbondioxidepercentasluminousasitisnow,so

inaplanet'satmosphereisanthetemperatureinVenus'early

indicatorofwateronthatplanet.atmospheremusthavebeenquiteabit

D.Venusprobablywasstruckbylower.Thuswatervaporwouldhave

roughlyasmanycometsasEarthwas.beenabletoliquefyandformoceans

onVenus.Butifwatervaporand

4.Theword"luminous'1inthepassagecarbondioxidewereoncesocommon

isclosestinmeaningtointheatmospheresofbothEarthand

A.denseVenus,whatbecameofEarth'scarbon

B.brightdioxide?Andwhathappenedtothe

C.largewateronVenus?

D.active

5.Whichofthesentencesbelowbest[Paragraph3]

expressestheessentialinformationinTheanswertothefirstquestionis

thehighlightedsentenceinthethatcarbondioxideisstillfoundIn

passage?IncorrectchoiceschangeabundanceonEarth,butnow,instead

themeaninginimportantwaysorofbeingintheformofatmospheric

leaveoutessentialinformation.carbondioxide,itiseitherdissolvedin

A.Thefirstquestiontobeansweredtheoceansorchemicallyboundinto

ishowEarth'satmosphericcarboncarbonaterocks,suchasthe

dioxideeithergotdissolvedinthelimestoneandmarblethatformedin

oceansorgotchemicallyboundintotheoceans.IfEarth