2026年托福《阅读》模拟试题及答案

2026年托福《阅读》模拟试题及答案Passage1TheDynamicsofCoralReefEcosystemsCoralreefsareamongthemostbiologicallydiverseandeconomicallyvaluableecosystemsonEarth.Oftenreferredtoasthe"rainforestsofthesea,"theysupportavastarrayofmarinelife,providinghabitat,shelter,andbreedinggroundsfornumerousspecies,includingfish,mollusks,andcrustaceans.However,theseintricatestructuresarenotmerelystaticgeologicalformations;theyareliving,breathingecosystemsgovernedbyadelicatebalanceofbiologicalandenvironmentalfactors.Thehealthandresilienceofcoralreefsarefundamentallydependentonasymbioticrelationshipbetweenthecoralpolypsandmicroscopicalgaeknownaszooxanthellae.Therelationshipbetweencoralpolypsandzooxanthellaeisaclassicexampleofmutualism,wherebothorganismsbenefit.Thecoralpolypsprovidethealgaewithaprotectedenvironmentandaccesstosunlight,whichisnecessaryforphotosynthesis.Inreturn,thealgaeproduceoxygenandhelpthecoraltoremovewastes.Mostimportantly,thezooxanthellaesupplythecoralwithorganicproductsofphotosynthesis,suchasglucose,glycerol,andaminoacids,whicharetheprimaryenergysourceforthecoral.Thisenergyproductionallowsthecoralpolypstodepositcalciumcarbonate,therebybuildingtherigidskeletalstructureofthereef.Itisestimatedthatzooxanthellaeprovideupto90%ofthecoral’senergyrequirements.Despitethisrobustpartnership,coralreefsarehighlysensitivetoenvironmentalchanges.Themostsignificantthreattotheirsurvivaliscoralbleaching,aphenomenonprimarilydrivenbyrisingseatemperatures.Whenwatertemperaturesriseevenslightly—oftenaslittleas1to2degreesCelsiusabovethenormalsummermaximum—thecoralbecomesstressed.Inresponsetothisthermalstress,thecoralpolypsexpeltheirzooxanthellae,causingthecoraltoturncompletelywhite.Whilethecoralisnotdeadatthisstage,itisunderseverestressandmoresusceptibletodisease.Withoutthealgae,thecorallosesitsprimarysourceoffoodandbeginstostarve.Ifthestressfulconditionspersistandthealgaedonotreturn,thecoralwilleventuallydie.Theimplicationsofcoralbleachingextendfarbeyondthelossofthecoralitself.Reefsprovidecriticalecosystemservices,suchascoastalprotection.Thecomplexstructuresofcoralreefsactasnaturalbarriersthatdissipatetheenergyofwaves,reducingerosionandprotectingshorelinesfromstormsandrisingsealevels.Thelossofreefswouldleavecoastalcommunitiesvulnerabletoincreasedfloodingandinfrastructuredamage.Furthermore,theeconomicimpactisprofound.Millionsofpeopledependonreefsforfoodthroughfishingandforincomethroughtourism.Thecollapseofreefecosystemswouldleadtofoodinsecurityandeconomicinstabilityinmanytropicalregions.Scientistsarecurrentlyresearchingvariousstrategiestomitigatetheeffectsofbleachingandenhancereefresilience.Oneareaoffocusisassistedgeneflow,wherecoralswithgreaterheattolerancearebredortransplantedtoreefsthatarestrugglingtosurvive.Anotherstrategyinvolvestherestorationofreefhabitatsusingcoralgardeningtechniques,wherefragmentsofhealthycoralaregrowninnurseriesandlateroutplantedontodegradedreefs.Whiletheseinterventionsofferhope,theyarenotasilverbullet.Thelong-termsurvivalofcoralreefsultimatelydependsonglobaleffortstoreducecarbonemissionsandstabilizetheclimate.Withoutaddressingtherootcauseofoceanwarming,localrestorationeffortsmayonlyprovidetemporaryrelief.Questions1-101.Theword"array"inthepassageisclosestinmeaningtoA.collectionB.formationC.displayD.texture2.Accordingtoparagraph2,howdozooxanthellaebenefitthecoralpolyps?A.Theyprotectthecoralfrompredators.B.Theyprovidethecoralwithessentialnutrientsandenergy.C.Theyhelpthecoraltoreproduce.D.Theyremovecalciumcarbonatefromthewater.3.Theword"mutualism"inthepassagereferstoA.arelationshipwhereoneorganismbenefitsattheexpenseoftheotherB.arelationshipwherebothorganismsbenefitC.arelationshipwhereoneorganismbenefitswhiletheotherisunaffectedD.arelationshipwherebothorganismsareharmed4.Whathappenstocoralduringtheprocessofbleaching?A.Thecoralpolypsdieimmediately.B.Thecoralabsorbsmoresunlighttocooldown.C.Thecoralexpelsthealgaelivinginitstissues.D.Thecoralchangesitsskeletalstructuretobecomesofter.5.Whichofthesentencesbelowbestexpressestheessentialinformationinthefollowingsentence?"Whenwatertemperaturesriseevenslightly—oftenaslittleas1to2degreesCelsiusabovethenormalsummermaximum—thecoralbecomesstressed."A.Coralstressiscausedbyasignificantdropinwatertemperatureduringthewinter.B.Asmallincreaseinwatertemperaturecancausesignificantstresstocoral.C.Coralisonlystressedwhenwatertemperaturesriseabove5degreesCelsius.D.Watertemperaturesfluctuatenaturally,andcoralisadaptedtothesechanges.6.Theword"dissipate"inthepassageisclosestinmeaningtoA.concentrateB.generateC.scatterD.increase7.Accordingtoparagraph4,whyarecoralreefsimportantforcoastalcommunities?A.Theyprovideasourceoffreshwater.B.Theyactasnaturalbarriersagainstwavesandstorms.C.Theyattracttouristswhospendmoneyonlocalinfrastructure.D.Theyincreasethewatertemperature,whichbenefitslocalfisheries.8.Whatcanbeinferredabouttherelationshipbetweencoralbleachingandthefishingindustry?A.Thefishingindustrycausescoralbleaching.B.Coralbleachinghasnoimpactonthefishingindustry.C.Thecollapseofreefsduetobleachingcouldleadtoadeclineinfishstocks.D.Fishermenaretheprimarygroupconductingresearchonbleaching.9.Lookatthefourletters[A,B,C,D]thatindicatewherethefollowingsentencecouldbeaddedtothepassage."Withoutthiscalciumcarbonateskeleton,thereefstructurewouldcollapse,eliminatingthehabitatforthousandsofspecies."Wherewouldthesentencebestfit?A.Thisenergyproductionallowsthecoralpolypstodepositcalciumcarbonate,therebybuildingtherigidskeletalstructureofthereef.[A]B.Itisestimatedthatzooxanthellaeprovideupto90%ofthecoral’senergyrequirements.[B]C.Despitethisrobustpartnership,coralreefsarehighlysensitivetoenvironmentalchanges.[C]D.Themostsignificantthreattotheirsurvivaliscoralbleaching,aphenomenonprimarilydrivenbyrisingseatemperatures.[D]10.Directions:Anintroductorysentenceforabriefsummaryofthepassageisprovidedbelow.CompletethesummarybyselectingtheTHREEanswerchoicesthatexpressthemostimportantideasinthepassage.Somesentencesdonotbelonginthesummarybecausetheyexpressideasthatarenotpresentedinthepassageorareminorideasinthepassage.Coralreefsarevitalecosystemsthatarecurrentlyfacingseverethreatsduetoenvironmentalchanges.______________________________________________________________________________A.Coralreefsrelyonasymbioticrelationshipwithalgaeforenergyandgrowth.B.Risingseatemperaturescausecoralbleaching,whichcanleadtothedeathofthecoral.C.Coralreefsarefoundinbothtropicalandpolarregionsoftheocean.D.Thelossofcoralreefswouldhavedevastatingeconomicandenvironmentalconsequences.E.Coralpolypscansurviveindefinitelywithoutthepresenceofzooxanthellae.F.Scientistsareexploringlocalrestorationmethods,butglobalclimateactionisessential.AnswersandExplanationsforPassage11.AExplanation:Inthephrase"vastarrayofmarinelife,""array"referstoalargegrouporvarietyofthings."Collection"istheclosestsynonym."Formation"impliesstructure,"display"impliesshowing,and"texture"impliesfeel,noneofwhichfitaswellas"collection."2.BExplanation:Paragraph2statesthatthealgae"supplythecoralwithorganicproductsofphotosynthesis...whicharetheprimaryenergysourceforthecoral."ThismatchesoptionB.3.BExplanation:Thetextdefinesmutualisminthecontextofthesentence:"aclassicexampleofmutualism,wherebothorganismsbenefit."OptionBisthedirectdefinition.4.CExplanation:Paragraph3explainsthatinresponsetothermalstress,"thecoralpolypsexpeltheirzooxanthellae,causingthecoraltoturncompletelywhite."Thisisthedefinitionofbleachingprovided.5.BExplanation:Theoriginalsentenceemphasizesthataverysmallrise(1-2degrees)causesstress.OptionBcapturesthiscause-and-effectrelationship:smallincrease=stress.OptionsA,C,andDcontradictthetextorchangethemeaning.6.CExplanation:"Dissipate"meanstodisperseorscatterenergy.Inthecontextofwaveshittingareef,thereefbreaksupthewaveenergy."Scatter"istheclosestsynonym."Concentrate"istheopposite.7.BExplanation:Paragraph4explicitlystates,"Thecomplexstructuresofcoralreefsactasnaturalbarriersthatdissipatetheenergyofwaves,reducingerosionandprotectingshorelines..."8.CExplanation:Paragraph4mentionsthatreefsprovide"habitat,shelter,andbreedinggroundsfornumerousspecies,includingfish"andthatthelossofreefswouldleadto"foodinsecurity."Therefore,itcanbeinferredthatifreefsdie(duetobleaching),fishpopulationswoulddecline,impactingthefishingindustry.9.AExplanation:Theinsertedsentencediscussestheimportanceofthecalciumcarbonateskeleton.ItfitsbestaftersentenceA,whichmentionsthatthecoraldepositscalciumcarbonatetobuildtheskeleton.Itlogicallyconnectstheactionofbuildingtheskeletontotheconsequenceofwhatwouldhappenwithoutit.10.A,B,FExplanation:A:Correct.Paragraph2detailsthesymbioticrelationshipessentialforsurvival.B:Correct.Paragraph3explainsbleachingcausedbytemperaturerise.C:Incorrect.Thepassagefocusesontropicalreefs;polarreefsarenotmentioned.D:Correct.Paragraph4discussestheeconomicandenvironmentalimpactsofreefloss.E:Incorrect.Paragraph3statesthatwithoutalgae,thecoralbeginstostarveandeventuallydies.F:Correct.Paragraph5discussesrestorationstrategiesandthenecessityofglobalclimateaction.Passage2TheIncaRoadSystem:EngineeringandEmpireTheIncaEmpire,whichflourishedinwesternSouthAmericafromtheearly15thcenturyuntiltheSpanishconquestinthe16thcentury,wasthelargestempireinpre-ColumbianAmerica.Atitspeak,theempirecoveredavastgeographicarea,includingpartsofmodern-dayPeru,Ecuador,Bolivia,Argentina,Chile,andColombia.Togovernandcontrolthisimmenseterritory,theIncasconstructedasophisticatedandextensiveroadnetworkknownastheQhapaqÑan.Thissystemofroadswasnotmerelyafeatofengineering;itwastheverybackboneoftheempire,facilitatingcommunication,trade,militarymovement,andtheintegrationofdiversecultures.TheIncaroadsystemspannedapproximately40,000kilometers,traversingsomeofthemostchallengingterrainsonEarth.ItwoundthroughhighAndeanmountains,crossedaridcoastaldeserts,andpenetrateddensetropicaljungles.Despitetheharshconditions,theroadswereremarkablywell-constructed.UnliketheRomanroads,whichweretypicallyflatandpavedwithstone,theIncaroadsvariedindesigntosuitthelocalenvironment.Inflatareas,theroadswereoftenstraightandpaved.Inmountainousregions,theengineersbuiltstaircasesandstonepathstonavigatesteepslopes.Tocrossdeepravinesandrivers,theIncasconstructedsuspensionbridgesmadeofwovengrassropes.Thesebridgesweremaintainedandreplacedannuallybylocalcommunities,ataskthatwasconsideredaformoflabortributetothestate.Oneoftheprimaryfunctionsoftheroadsystemwasmilitarydefenseandrapidtroopdeployment.TheIncaarmycouldmovequicklyacrosstheempiretoquellrebellionsordefendagainstexternalthreats.Theroadsallowedfortheefficienttransportofsoldiersandsupplies.Alongthemainroutes,theIncasbuiltstorehousesknownastambosandmilitaryinstallationscalledtampu.Thesestructuresensuredthattroopshadaccesstofood,weapons,andshelterduringtheircampaigns.ThespeedatwhichtheIncamilitarycouldtravelwaslegendary;messagesandfreshsuppliescouldberelayedacrosshundredsofkilometersinasingledayusingasystemofrelayrunnerscalledchasquis.Tradewasanothervitalfunctionfacilitatedbytheroadnetwork.AlthoughtheIncaeconomywaslargelybasedonreciprocityandstateredistributionratherthanamarketsystemwithcurrency,goodsmovedextensivelythroughouttheempire.Localresources,suchastextiles,ceramics,metals,andfoodstuffs,weretransportedtothecapital,Cusco,ordistributedtootherregionswheretheywereneeded.Theroadsalsoallowedforthemovementofpeople,facilitatingthemit'asystem,aformofmandatorylaborservice.Citizenswererequiredtoworkonstateprojects,suchasroadmaintenanceoragriculturalwork,andtheroadsenabledthetransportationoftheselaborerstotheirassignedworksites.Theconstructionandmaintenanceoftheroadsweremadepossiblethroughthemit'asystem.Thislabortaxrequiredeverymalesubjecttoworkforthestateforaspecifiedperiodeachyear.ThismobilizationoflaborallowedtheIncastoundertakemassivepublicworksprojectswithouttheuseofmoneyorwheeledvehicles.ItisimportanttonotethattheIncasdidnotusethewheelfortransportation,nordidtheyhavedraftanimalslikehorses.Therefore,allgoodsweretransportedbyhumanportersorllamas.Theroadsweredesignedspecificallyforfootandllamatraffic;theywereoftentoosteepforwheeledcartseveniftheIncashadpossessedthem.TheSpanishconquistadors,whoarrivedinthe16thcentury,wereastoundedbythequalityandextentoftheIncaroads.Theyfrequentlyusedtheexistingnetworktoadvancetheirconquestandtransporttheirowntroops.Whiletheintroductionofhorsesandwheeledcartseventuallyalteredtheusageoftheroads,thefundamentalinfrastructurelaidbytheIncasremainedtheprimarytransportationnetworkintheAndesforcenturies.Today,remnantsoftheQhapaqÑanstillexist,servingasatestamenttotheingenuityandorganizationalpoweroftheIncacivilization.In2014,UNESCOrecognizedtheculturalsignificanceoftheroadsystembydesignatingitaWorldHeritageSite.Questions11-2011.Theword"facilitating"inthepassageisclosestinmeaningtoA.observingB.makingeasierC.preventingD.delaying12.Accordingtoparagraph2,howdidIncaroadconstructiondifferfromRomanroadconstruction?A.Incaroadswerealwayspavedwithstone,whileRomanroadswerenot.B.Romanroadsweredesignedforwheeledvehicles,whileIncaroadswerenot.C.Incaroadswereprimarilybuiltindeserts,whileRomanroadswereinmountains.D.RomanroadswerelongerandcoveredmoreterritorythanIncaroads.13.Theword"traverse"inthepassageisclosestinmeaningtoA.avoidB.mapC.crossD.ignore14.Whydoestheauthormentionsuspensionbridgesmadeofwovengrassropes?A.ToillustratetheresourcefulnessofIncaengineeringindifficultterrain.B.Toarguethatthesebridgeswereunsafeandneededfrequentreplacement.C.TocomparethemnegativelytothestonebridgesbuiltbytheRomans.D.TosuggestthattheIncaslackedthetechnologytoworkwithstone.15.Accordingtoparagraph3,whatwastheroleofthechasquis?A.Theyweresoldierswhoguardedthetambos.B.Theywereengineerswhodesignedtheroads.C.Theywererelayrunnerswhocarriedmessagesandsupplies.D.Theywerelocalgovernorswhocollectedtaxes.16.WhichofthefollowingcanbeinferredabouttheIncaeconomyfromparagraph4?A.Itreliedheavilyonastandardizedcurrencysystem.B.Itwasamarketeconomywherepricesweredeterminedbysupplyanddemand.C.Itdependedonthestateredistributinggoodsandlabor.D.Itwasisolatedanddidnottradewithneighboringregions.17.Accordingtoparagraph5,whyweretheroadsdesignedforfootandllamatraffic?A.TheIncaslackedthewheelanddraftanimalslikehorses.B.Llamasweretheonlyanimalscapableofclimbingsteepmountains.C.Theroadsweretoonarrowtoaccommodateanyotherformoftransport.D.TheIncasbelievedthatusingwheelswoulddamagethespiritualintegrityoftheroad.18.Lookatthefourletters[A,B,C,D]thatindicatewherethefollowingsentencecouldbeaddedtothepassage."Thepreservationofthesestructureswascrucialforthecontinuedfunctioningoftheempire'slogisticalnetwork."Wherewouldthesentencebestfit?A.Alongthemainroutes,theIncasbuiltstorehousesknownastambosandmilitaryinstallationscalledtampu.[A]B.Thesestructuresensuredthattroopshadaccesstofood,weapons,andshelterduringtheircampaigns.[B]C.ThespeedatwhichtheIncamilitarycouldtravelwaslegendary...[C]D....messagesandfreshsuppliescouldberelayedacrosshundredsofkilometersinasingleday...[D]19.Theword"astounded"inthepassageisclosestinmeaningtoA.confusedB.disappointedC.amazedD.indifferent20.Directions:Anintroductorysentenceforabriefsummaryofthepassageisprovidedbelow.CompletethesummarybyselectingtheTHREEanswerchoicesthatexpressthemostimportantideasinthepassage.Somesentencesdonotbelonginthesummarybecausetheyexpressideasthatarenotpresentedinthepassageorareminorideasinthepassage.TheIncaroadsystemwasacriticalcomponentoftheempire'sinfrastructureandsuccess.______________________________________________________________________________A.Theroadswerebuiltusingthewheelanddraftanimalstotransportheavystones.B.Thenetworkconnecteddiverseregionsandenabledmilitary,trade,andadministrativefunctions.C.Theengineeringadaptedtovariousterrains,includingmountainsanddeserts.D.TheSpanishconquistadorsdestroyedtheroadsimmediatelyuponarrival.E.Themit'alaborsystemwasessentialforbuildingandmaintainingtheroads.F.Theroadswereusedexclusivelyforreligiousceremoniesandprocessions.AnswersandExplanationsforPassage211.BExplanation:"Facilitating"meanstomakeanactionorprocesseasier.Inthetext,theroadsmadecommunication,trade,etc.,easier."Makingeasier"isthecorrectsynonym.12.BExplanation:Paragraph2contrastsIncaroadswithRomanroads,notingthatRomanroadswere"flatandpaved,"whileIncaroadsvaried.Paragraph5explicitlystates,"ItisimportanttonotethattheIncasdidnotusethewheelfortransportation...Therefore,allgoodsweretransportedbyhumanportersorllamas."Romanroadswerefamouslydesignedforcarts/wagons(wheels).13.CExplanation:"Traverse"meanstotravelacrossorthroughanarea."Cross"istheclosestsynonym.Thesentencediscussestheroadsgoingthroughmountains,deserts,andjungles.14.AExplanation:Theauthormentionsthegrassbridgesinthecontextofcrossing"deepravinesandrivers"in"challengingterrains."ThishighlightshowtheIncasusedavailablematerials(grass)tosolveengineeringproblems,demonstratingresourcefulness.15.CExplanation:Paragraph3statesthat"messagesandfreshsuppliescouldberelayed...usingasystemofrelayrunnerscalledchasquis."16.CExplanation:Paragraph4states,"theIncaeconomywaslargelybasedonreciprocityandstateredistributionratherthanamarketsystemwithcurrency."ThissupportsoptionC.17.AExplanation:Paragraph5explicitlystates:"ItisimportanttonotethattheIncasdidnotusethewheelfortransportation,nordidtheyhavedraftanimalslikehorses.Therefore,allgoodsweretransportedbyhumanportersorllamas."Thislackoftechnologydictatedthedesign.18.BExplanation:Theinsertedsentencediscussestheimportanceofpreserving"thesestructures."Itrefersbackto"tambosandmilitaryinstallations"mentionedintheprevioussentence.Placingitat[B]linksthefunctionofthestructures(providingaccess)withtheneedfortheirpreservationforthenetworktowork.19.CExplanation:"Astounded"meansgreatlysurprisedorshocked,ofteninapositiveorimpressedmanner."Amazed"istheclosestsynonym.ThecontextistheSpanishreactiontothequalityoftheroads.20.B,C,EExplanation:A:Incorrect.Paragraph5statestheIncasdidNOTusethewheel.B:Correct.Paragraph1and3detailthefunctions(military,trade,integration).C:Correct.Paragraph2describestheadaptationtomountains,deserts,andjungles.D:Incorrect.Paragraph6saystheSpanishusedtheroads;theydidn'tdestroythemimmediately.E:Correct.Paragraph5explainsthatthemit'alaborsystemenabledtheconstruction.F:Incorrect.Theroadswereusedformilitary,trade,andadministration,notexclusivelyforreligion.Passage3ThePossibilityofLifeonEuropaJupiter'smoonEuropaisoneofthemostcompellingtargetsinthesearchforextraterrestriallifewithinoursolarsystem.SlightlysmallerthanEarth'smoon,Europahasanicysurfacethatisamongthesmoothestinthesolarsystem,lackingthecratersandmountainstypicalofothersolidbodies.Thissmoothnesssuggeststhatthesurfaceisgeologicallyyoungandhasbeenrecentlyresurfaced,likelybyicymaterialrisingfrombelow.Beneaththisfrozencrustliesaglobaloceanofliquidwater,containingroughlytwicethevolumeofwaterfoundinallofEarth'soceanscombined.Thepresenceofthisvast,subsurfaceocean,coupledwithasourceofenergy,makesEuropaaprimecandidateforharboringlife.TheexistenceofaliquidwateroceanonEuropawasfirsthypothesizedbasedondatafromtheVoyagerspacecraftinthe1970s,butitwastheGalileomissioninthe1990sthatprovidedcompellingevidence.Galileo'smagneticfieldmeasurementsindicatedthatEuropahasaninducedmagneticfield.Thistypeofmagneticfieldiscreatedwhenanelectricallyconductivefluid,suchasasaltyocean,movesthroughahostplanet'smagneticfield.SinceEuropa'sownmagneticfieldisweak,theinducedfieldstronglysuggeststhepresenceofasaltylayerbeneaththeice.Furthermore,imagesofEuropa'ssurfaceshowfeaturesresemblingicefloesonEarth,similartothoseseeninpolarregions.These"chaosterrains"appeartobeblocksofcrustthathavebrokenapart,rotated,andrefrozen,implyingthattheiceshellisfloatingonaliquidlayer.Oneofthecriticalrequirementsforlifeasweknowitisasourceofenergytodrivemetabolicprocesses.OnEarth,theprimarysourceofenergyissunlight,whichfuelsphotosynthesis.However,Europa'soceanisdeepbeneathathickicecrustthatlikelyblocksmostsunlight.Therefore,lifeonEuropawouldhavetorelyonalternativeenergysources.Scientistsproposethatchemicalenergycouldbeavailablethroughhydrothermalventsontheoceanfloor.OnEarth,hydrothermalventssupportrichecosystemsthatthriveindependentlyofsunlight.Chemosyntheticbacteriaattheseventsusechemicalreactions,suchastheoxidationofhydrogensulfide,toproduceorganicmatter.IfsimilargeologicalprocessesareactiveonEuropa'sseafloor,theycouldprovidethenecessaryenergytosustainmicrobiallife.Anotherpotentialenergysourceistidalheating.EuropaorbitsJupiterinanellipticalpathduetothegravitationalinfluenceofJupiteranditsotherlargemoons,particularlyIoandGanymede.AsEuropa'sdistancefromJupiterchanges,theplanet'simmensegravitystretchesandsqueezesthemoon,generatinginternalfrictionandheat.ThistidalheatingisresponsibleforkeepingEuropa'soceanliquidandcouldalsodrivegeologicalactivityontheseafloor,suchasvolcanismorhydrothermalventformation.Thisconstantflexingensuresthattheinteriorremainsdynamic,potentiallycyclingnutrientsandorganiccompoundsbetweenthecore,theocean,andtheiceshell.ThechemicalcompositionofEuropa'ssurfacealsoprovidescluesaboutitspotentialhabitability.Spectroscopicanalysishasdetectedthepresenceofwaterice,carbondioxide,andvarioussalts,includingmagnesiumsulfate(Epsomsalts).Thereisalsoevidenceofhydratedminerals,suchasclayminerals,onthesurface.Thesematerialsmayhaveoriginatedfromtheoceanbelowandweretransportedtothesurfacethroughgeologicalactivityorimpacts.Thedetectionofthesecompoundsissignificantbecausetheycontaintheelementsessentialforlife,suchascarbon,hydrogen,oxygen,nitrogen,sulfur,andphosphorus.Ifthesematerialsarepresentintheocean,theycouldserveasthebuildingblocksforbiologicalmolecules.FuturemissionsaimtodefinitivelydeterminewhetherEuropaishabitable.NASA'supcomingEuropaClippermission,scheduledforthe2020s,willconductmultipleflybysofthemoontoperformdetailedreconnaissanceofitscompositionandthestructureofitsiceshellandocean.Thespacecraftwillmeasurethethicknessoftheiceshell,mapthesurfaceinhighresolution,andanalyzethecompositionofmaterialplumesthatmaybeeruptingfromtheocean.FollowingClipper,theEuropeanSpaceAgency'sJUICEmissionwillalsostudyJupiter'sicymoons.Thesemissionsrepresentthenextstepsinhumanity'squesttoanswertheprofoundquestionofwhetherwearealoneintheuniverse.Questions21-3021.Theword"compelling"inthepassageisclosestinmeaningtoA.confusingB.convincingC.complexD.contradictory22.Accordingtoparagraph2,whatevidencesuggeststhepresenceofasubsurfaceoceanonEuropa?A.Thelackofcratersonthesurface.B.Thedetectionofaninducedmagneticfield.C.Thereflectionofsunlightofftheicysurface.D.Thepresenceofathickatmosphere.23.Whydoestheauthormention"chaosterrains"inparagraph2?A.TodescribetheimpactofmeteoritesonEuropa'ssurface.B.Toarguethattheiceshellisextremelythickandsolid.C.Tosupportthehypothesisthattheicefloatsonliquidwater.D.Toexplainwhythesurfaceissocold.24.Accordingtoparagraph3,whyissunlightanunlikelyenergysourceforlifeonEuropa?A.ThemoonistoofarfromtheSuntoreceiveanyheat.B.Thethickicecrustpreventssunlightfromreachingtheocean.C.Theoceanistoodeepforsunlighttopenetrate.D.LifeonEuropahasevolvedtoavoidsunlight.25.Theword"thrive"inthepassageisclosestinmeaningtoA.surviveB.growC.originateD.float26.WhatprocesscreatestheinternalheatthatkeepsEuropa'soceanliquid?A.Radioactivedecayinthemoon'score.B.Solarradiationheatingthesurfaceice.C.TidalheatingcausedbyJupi