2025年11月托福真题及答案

2025年11月托福真题及答案

ReadingSection

Passage1

TheEvolutionofVisioninTrilobites

Trilobites,extinctmarinearthropodsthatthrivedfromtheCambriantothePermianperiods,areamongthemostdistinctivecreaturesofthePaleozoicera.Oneoftheirmostremarkablefeatureswastheireyes,whichrepresentsomeoftheearliestandmostsophisticatedvisualsystemsintheanimalkingdom.Thestudyoftrilobitevisionprovidessignificantinsightsintotheevolutionarypressuresandecologicaladaptationsofearlymarinelife.

Theeyesoftrilobitesweretypicallycompoundeyes,composedofnumerousindividualunitscalledommatidia.Thesestructureswerecalcified,meaningtheyweremadeofcalciumcarbonate,whichallowedthemtobeexceptionallywell-preservedinthefossilrecord.Thismineralizationdistinguishestrilobiteeyesfromthecompoundeyesofmoderninsectsandcrustaceans,whichareprimarilychitinous.Thecalcitelenseswerearrangedinaprecisegeometricpattern,formingavisualsurfacethatvariedsignificantlyamongdifferenttrilobitespecies.

Therewerethreeprimarytypesofeyearrangementsintrilobites:holochroal,schizochroal,andphacopate.Holochroaleyes,foundintheorderAgnostida,consistedofalargenumberofsmalllenses(sometimesexceeding15,000)thatwereindirectcontactwithoneanother,coveredbyasinglecontinuouscorneallayer.Thisarrangementissimilartotheeyesofmoderninsectsandlikelyprovidedawidefieldofviewbutperhapswithlowerresolution.Incontrast,schizochroaleyes,characteristicoftheorderPhacopida,featuredfewer,largerlensesthatwereseparatedfromeachotherbythicksclera(coating).Eachlenshaditsownindividualcornea.Thisseparationmayhaveallowedforbetterlightgatheringindimenvironmentsandimprovedfocus,suggestinganadaptationtodeeperormurkierwaters.Thethirdtype,phacopateeyes,isessentiallyavariationofschizochroaleyeswherethelensesareevenmoredeeplysetandthenumberoflensesisfurtherreduced.

Theevolutionarytrajectoryoftrilobiteeyessuggestsacomplexinterplaybetweenenvironmentalfactorsandpredatory-preyrelationships.DuringtheCambrianexplosion,theemergenceofsophisticatedvision,oftentermedthe"LightSwitch"hypothesis,isthoughttohavedrivenanarmsrace.Predatorsdevelopedbettereyestohunt,andpreydevelopedbettereyestoevadedetection.Trilobites,beingbothpredatorsandscavengers,benefitedimmenselyfromacutevision.Thedevelopmentofschizochroaleyesincertainlineagesisparticularlyintriguing.Somepaleontologistsarguethatthethicksclerasurroundingeachlensactedasasortof"sunglasses,"reducingglareandallowingthetrilobitetospotpreyagainstthebrightsurfacelightwhiledwellingindeeperwater.Thisabilitywouldhaveprovidedasignificanttacticaladvantage.

Furthermore,theplacementofeyesonthetrilobitebodyvaried.Mosthadeyeslocatedonthedorsalsurfaceofthecephalon(headshield),providingapanoramicviewoftheirsurroundings.However,somespeciesevolvedeyesonstalks,similartomoderncrabs.Thesestalkeyeselevatedthevisualsensorsabovetheseafloor,enablingtheanimaltoseewhileremainingpartiallyburiedinthesedimenttohidefromlargerpredators.Thisadaptationhighlightsthedualselectivepressuresoftheneedforvigilanceandtheneedforconcealment.

TheeventualdeclineoftrilobitesduringthePermianextinctioneventalsomarkedtheendofthisuniqueexperimentincalcifiedvision.Whiletheexactcauseoftheirextinctionisdebated—rangingfromanoxiatoclimatechange—theiropticalsystemsdidnotsurvive.Modernarthropodsabandonedthecalcitelensapproach,likelyduetoitsmetaboliccostormechanicallimitationscomparedtotheflexibilityofprotein-basedlenses.Nevertheless,thefossilizedeyesoftrilobitesremainatestamenttothediversityofevolutionarysolutionstothechallengeofseeingtheancientoceans.

Questions:

1.Theword"distinctive"inthepassageisclosestinmeaningto:

A.Common

B.Unique

C.Ancient

D.Fossilized

2.Accordingtoparagraph2,whyaretrilobiteeyeswell-preservedinthefossilrecord?

A.Theywerelocatedonthehardheadshield.

B.Theywerecomposedofcalciumcarbonate.

C.Theywerecoveredbyathicklayerofchitin.

D.Theywereburieddeepinthesediment.

3.Theword"This"inthepassagerefersto:

A.Thegeometricpatternofthelenses.

B.Themineralizationofthelenses.

C.Theuseofcalciumcarbonate.

D.Thearrangementofommatidia.

4.Whichofthefollowingistrueofholochroaleyes?

A.Theyhadfewer,largerlensesthanschizochroaleyes.

B.TheywerefoundprimarilyintheorderPhacopida.

C.Theyconsistedoflensescoveredbyasinglecontinuouscornea.

D.Theywereadaptedfordeep-waterenvironments.

5.Whydoestheauthormentionthe"LightSwitch"hypothesisinparagraph4?

A.Toexplainwhytrilobiteseventuallybecameextinct.

B.Toillustratetheimpactofvisiononthepredator-preydynamic.

C.ToprovethattrilobitesweretheonlypredatorsintheCambrian.

D.Tocontrasttrilobitevisionwithmoderninsectvision.

6.Accordingtoparagraph4,whatpossiblefunctiondidthethicksclerainschizochroaleyesserve?

A.Itprotectedtheeyefromsedimentabrasion.

B.Itactedasa"sunglasses"effecttoreduceglare.

C.Itallowedtheeyetomoveindependentlyofthehead.

D.Itincreasedthemetabolicefficiencyoftheeye.

7.Whatcanbeinferredabouttrilobiteswithstalkeyesfromparagraph5?

A.Theywerelikelyblindinbrightsunlight.

B.Theylivedinenvironmentswherehidingwasnecessary.

C.Theywereexclusivelyscavengersratherthanpredators.

D.Theycouldnotseedirectlybehindthemselves.

8.Accordingtothepassage,whydidmodernarthropodslikelyabandoncalcitelenses?

A.Thelensesweretooheavytosupportonland.

B.Thegeneticcodeforproducingthemwaslost.

C.Protein-basedlensesofferedmoreflexibilityandlowermetaboliccost.

D.Calcitelensesweresusceptibletodissolvinginsaltwater.

9.Lookatthefoursquares[■]thatindicatewherethefollowingsentencecouldbeaddedtothepassage.

"Thisadaptationsuggeststhatthesecreatureswereactivehuntersneedingprecisedepthperception."

Wherewouldthesentencebestfit?

A.[A](Endofparagraph2)

B.[B](Endofparagraph3)

C.[C](Endofparagraph4)

D.[D](Endofparagraph5)

10.Directions:Anintroductorysentenceforabriefsummaryofthepassageisprovidedbelow.CompletethesummarybyselectingtheTHREEanswerchoicesthatexpressthemostimportantideasinthepassage.Somesentencesdonotbelonginthesummarybecausetheyexpressideasthatarenotpresentedinthepassageorareminorideasinthepassage.

Trilobitespossessedauniqueandhighlydevelopedvisualsystemthathasbeenextensivelystudiedthroughfossils.

____

____

____

AnswerChoices:

A.Trilobiteeyesweremadeofcalcite,unlikethechitinouseyesofmodernarthropods.

B.Theprimarydietoftrilobitesconsistedofsoft-bodiedwormsfoundontheoceanfloor.

C.Differenteyetypes,suchasholochroalandschizochroal,offeredvariousvisualadvantages.

D.Theevolutionoftrilobitevisionwasdrivenbyecologicalfactorslikepredationandlightavailability.

E.Trilobitesarethedirectancestorsofmodernhorseshoecrabs.

F.Stalkeyesallowedtrilobitestoseewhilehidingfrompredators.

Passage2

TheImpactofthePrintingPressontheRenaissance

TheinventionofthemovabletypeprintingpressbyJohannesGutenbergaround1440iswidelyregardedasoneofthemostpivotaleventsinhumanhistory,markingadecisivetransitionfromthemedievaleratotheearlymodernperiod,ortheRenaissance.Whilemanuscriptculturehadpreservedknowledgeforcenturies,itwasinherentlyslow,expensive,andpronetohumanerror.Theprintingpressrevolutionizedtheproductionofbooks,leadingtoanexplosionofinformationthattransformedEuropeansociety,religion,andintellectuallife.

BeforeGutenberg,bookswerehand-copiedbyscribes,usuallymonksinmonasteries.Thislabor-intensiveprocessmeantthatbookswereluxuryitemsaccessibleonlytothewealthyandtheclergy.ThecontentofthesemanuscriptswaslargelycontrolledbytheChurch,whichprioritizedreligioustexts.Consequently,literacyratesoutsidetheecclesiasticalspherewereremarkablylow.Theprintingpressdismantledthismonopoly.Bymechanizingthebookproductionprocess,Gutenbergdrasticallyreducedthecostandtimerequiredtocreateabook.Whatoncetookmonthstocopycouldnowbeproducedinweeksinmultiplecopies.

Theimmediateeconomicimpactwasprofound.Theprintingindustrybecameacommercialenterprise,centeredinitiallyincitieslikeMainz,Venice,andParis.Printersneededpaper,ink,andtype,stimulatingrelatedindustries.Theriseofthe"bookmarket"meantthatauthorscouldpotentiallyearnalivingfromwriting,shiftingthepatronagesystemfromtheChurchandaristocracytoabroader,albeitstillliterate,public.Thiseconomicshiftfosteredagrowingmiddleclassthatvaluededucationandself-improvement.

Intellectually,theprintingpressfacilitatedtherapiddisseminationofhumanistideas.RenaissanceHumanism,withitsfocusonrecoveringtheclassicalknowledgeofGreeceandRome,reliedontheaccuratereproductionoftexts.PrintededitionsofLatinandGreekclassicswerefarmoreconsistentthanhand-copiedversions,whichoftencontainedscribal"corrections"orerrorsthatcompoundedovertime.Scholarscouldnowcomparetextsmoreeasily,leadingtoadvancesinphilologyandcriticism.Furthermore,thestandardizationofvernacularlanguages—suchasGerman,French,andEnglish—helpedforgeasenseofnationalidentityandculturalunity.

PerhapsthemostsignificantsociopoliticalconsequenceoftheprintingpresswastheProtestantReformation.In1517,MartinLuthernailedhisNinety-fiveThesestothechurchdoorinWittenberg.Whilethiswasatraditionalactofacademicdisputation,theprintingpressensuredthatLuther'sideasspreadthroughoutGermanyandbeyondwithinweeks.Pamphletsandwoodcuts,oftenillustratedfortheilliteratemasses,allowedcomplextheologicaldisputestoenterthepublicsphere.TheCatholicChurchattemptedtorespondwithcensorshipandtheIndexofProhibitedBooks,butthetechnologyofprinthadirrevocablydecentralizedthecontrolofinformation.Theprintedwordbecameapowerfultoolforreligiousandpoliticaldissent.

ScientificRevolution

TheprintingpressalsolaidthegroundworkfortheScientificRevolution.Scientificprogressdependsontheaccuratetransmissionofdataandtheabilityofscientiststobuildupontheworkofothers.Printallowedfortheinclusionofdetaileddiagrams,mathematicaltables,andmapsthatweredifficulttoreplicatebyhand.WorksbyCopernicus,Vesalius,andGalileoreachedawideaudienceofnaturalphilosophers.Thereliabilityofprinteddatameantthatexperimentscouldbeverifiedandrepeated,acornerstoneofthescientificmethod.Withouttheabilitytowidelyshareandstandardizescientificknowledge,thecollaborativeandcumulativenatureofmodernsciencewouldhavebeenimpossible.

Inconclusion,theprintingpresswasnotmerelyatechnologicalinnovationbutacatalystforwidespreadsocietalchange.ItbroketheChurch'sholdonknowledge,empoweredthemiddleclass,standardizedlanguages,fueledreligiousreform,andenabledscientificinquiry.Thetransitionfromamanuscriptculturetoaprintcultureredefinedhowpeoplelearned,communicated,andunderstoodtheworld.

Questions:

11.Theword"pivotal"inthepassageisclosestinmeaningto:

A.Insignificant

B.Secondary

C.Crucial

D.Ancient

12.Accordingtoparagraph2,howdidtheprintingpressaffecttheaccessibilityofbooks?

A.Itmadebooksmoreexpensiveduetothecostofmachinery.

B.ItrestrictedaccesstothosewhocouldreadLatin.

C.Itmadebookscheaperandmoreavailabletothenon-clergy.

D.Ithadlittleeffectontheliteracyratesofthepeasantry.

13.Whydoestheauthormention"paper,ink,andtype"inparagraph3?

A.TolisttherawmaterialsGutenberginvented.

B.Toexplainthetechnicalprocessofprinting.

C.Toillustratetheeconomicstimulationcausedbytheprintingindustry.

D.Toshowwhybooksremainedsomewhatexpensive.

14.Theword"consistency"inthepassageisclosestinmeaningto:

A.Accuracy

B.Uniformity

C.Frequency

D.Duration

15.Accordingtoparagraph4,howdidprintingcontributetothedevelopmentofnationalidentity?

A.BytranslatingtheBibleintovernacularlanguages.

B.Bystandardizingvernacularlanguagesthroughprint.

C.Byallowingnewstotravelacrossbordersquickly.

D.Byreducingthepowerofthemonarchy.

16.WhatcanbeinferredabouttheCatholicChurch'sresponsetotheprintingpressfromparagraph5?

A.Theyembracedthetechnologytospreadtheirownmessage.

B.Theywereunabletocontrolthespreadofdissentdespitecensorshipefforts.

C.TheyimmediatelybannedallprintingpressesinEurope.

D.Theyencouragedtheprintingofseculartextstodistractpeople.

17.Accordingtoparagraph6,whywastheprintingpressessentialfortheScientificRevolution?

A.Itallowedscientiststopublishtheirworkanonymously.

B.Itenabledtheaccuratereproductionofdiagramsanddataforverification.

C.Itreducedthecostofscientificequipment.

D.ItforcedscientiststolearnLatintocommunicate.

18.WhichofthefollowingisNOTmentionedinthepassageasaneffectoftheprintingpress?

A.Thegrowthofaliteratemiddleclass.

B.ThedeclineoftheuseofLatinasascholarlylanguage.

C.ThespreadofProtestantideas.

D.Theadvancementofthescientificmethod.

19.Theword"irrevocably"inthepassageisclosestinmeaningto:

A.Temporarily

B.Reversibly

C.Permanently

D.Violently

20.Insertsentence:"Thisshiftinpatronageallowedforawiderdiversityoftopicstobepublished."

Wherewoulditbestfit?

A.After"literate,public"inparagraph3.

B.After"humanistideas"inparagraph4.

C.After"scientificinquiry"intheconclusion.

D.Attheveryendofthepassage.

Passage3

ThermoregulationinMarineMammals

Marinemammals,includingcetaceans(whales,dolphins),pinnipeds(seals,sealions),andsirenians(manatees),faceauniquephysiologicalchallenge:maintainingastableinternalbodytemperatureinwaterthatconductsheatawayfromthebodymuchfasterthanair.Waterhasathermalconductivityapproximately25timesgreaterthanair.Consequently,marinemammalshaveevolvedsophisticatedthermoregulatoryadaptationstoconserveheatincoldenvironmentsand,insomecases,todissipateheatintropicalwaters.

Theprimarydefenseagainstheatlossisathicklayerofsubcutaneousfatknownasblubber.Blubberisadense,vascularizedlayeroffatlocatedbeneaththeskinandabovethemusculature.Itservesasaninsulator,reducingtherateofheatlosstothesurroundingwater.Thethicknessofblubbervariesamongspeciesandseasons;forexample,Arcticbowheadwhalesmayhaveablubberlayerupto50centimetersthick,whiledolphinsinwarmerwatershavemuchthinnerlayers.Unlikethefurofterrestrialmammals,blubberissmoothandstreamlined,reducingdragwhileswimming,whichiscrucialforenergyefficiency.

Inadditiontoblubber,manymarinemammalsutilizeaspecializedcirculatorysystemknownasacounter-currentheatexchanger.Intheextremities(flippers,flukes,anddorsalfins),arteriescarryingwarmbloodfromthehearttraveldirectlyalongsideveinscarryingcoldbloodbackfromtheskinsurface.Asthewarmbloodflowsdowntheartery,ittransfersheattothecoolervenousbloodreturningtothebodycore.Thismechanismcoolsthebloodbeforeitreachestheexposedextremities,therebyminimizingheatlosstothewater.Simultaneously,itwarmsthevenousbloodbeforeitreturnstotheheart,helpingtomaintainthecoretemperature.Thisadaptationisparticularlyvitalforanimalslikepenguinsandseals,whichrestoniceorswiminfreezingwater.

Whileretainingheatistheprimaryconcernforpolarspecies,avoidingoverheating(hyperthermia)isasignificantchallengeforlarge,activemarinemammals,particularlythosewithhighmetabolicratesorthoselivinginwarmerclimates.Largewhaleshavealowsurface-area-to-volumeratio(theBergmann'srule),whichhelpsthemretainheatbutcanleadtooverheatingduringvigorousactivityorinwarmcurrents.Todissipateheat,marinemammalscanincreasebloodflowtotheskinsurface,bypassingthecounter-currentexchangers.Thisallowsexcessbodyheattobereleasedintotheenvironment.Somespecies,likethebottlenosedolphin,alsousetheirflippersanddorsalfinsas"radiators,"increasingbloodflowtothesethin,highlyvascularizedareastodumpheat.

Behavioraladaptationsalsoplayacriticalroleinthermoregulation.Manyspeciesmigrateseasonallytostaywithinoptimaltemperatureranges.Forinstance,graywhalesmigratefromthecoldfeedinggroundsoftheArctictothewarmbreedinglagoonsofBajaCalifornia,andbackagain.Conversely,inhotconditions,marinemammalsmayreducetheiractivitylevelstominimizemetabolicheatproduction.Somespecies,likeseaotters,whichlackthickblubber,relyondensefurandbehavioralmechanismssuchasfloatingontheirbackstoconserveheat,andhuddlingtogetheringroups.

Themetabolicrateofmarinemammalsisgenerallyhigherthanthatofterrestrialmammalsofsimilarsize,aphenomenonknownasthe"Kleiber'sLaw"scaling.Thiselevatedmetabolismgeneratessubstantialinternalheat,whichaidsinthermoregulationincoldwaterbutrequiresefficientcoolingmechanismsinwarmwater.Thebalancebetweenheatproductionandheatdissipationisadelicatephysiologicaltightropethattheseanimalsmustwalktosurviveindiverseaquaticenvironments.

Questions:

21.Theword"conducts"inthepassageisclosestinmeaningto:

A.Transmits

B.Blocks

C.Generates

D.Absorbs

22.Whydoestheauthormentionthethermalconductivityofwaterinparagraph1?

A.Toexplainwhymarinemammalsneedblubber.

B.Tocomparewatertemperaturetoairtemperature.

C.Tosuggestthatmarinemammalsarecold-blooded.

D.Toillustratethedifficultyofkeepingcoolinwater.

23.Accordingtoparagraph2,whatisanadvantageofblubberoverfurformarinemammals?

A.Blubberprovidesbettercamouflage.

B.Blubberreducesdragwhileswimming.

C.Blubberiseasiertogrowthanfur.

D.Blubberdoesnotrequirevascularization.

24.Howdoesthecounter-currentheatexchangerwork?

A.Itstoresheatinthefatlayerforlateruse.

B.Ittransfersheatfromarteriestoveinsintheextremities.

C.Itincreasesbloodflowtotheskintoreleaseheat.

D.Itgeneratesheatthroughmusclecontractions.

25.Theword"vital"inthepassageisclosestinmeaningto:

A.Optional

B.Essential

C.Fatal

D.Minimal

26.Accordingtoparagraph4,howdolargewhalesdissipateexcessheat?

A.Byreducingtheirmetabolicrate.

B.Byincreasingbloodflowtotheskin.

C.Bysheddingtheirblubberlayer.

D.Bymovingtodeeper,colderwater.

27.Whatistheprimaryreasonseaottershuddletogether?

A.Toprotectagainstpredators.

B.Toconserveheatduetolackofblubber.

C.Tosharefoodresources.

D.Tosynchronizebreedingcycles.

28.Thepassagementions"Bergmann'srule"inparagraph4.Thisrulehelpsexplain:

A.Whysmallanimalsloseheatfaster.

B.Whylargewhalesarepronetooverheating.

C.Whydolphinshavethinblubber.

D.Whymigrationisnecessary.

29.Whichofthefollowingcanbeinferredaboutmarinemammalsfromthepassage?

A.Theyareunabletosurviveintropicalwaterswithoutblubber.

B.Theirmetabolicrateislowerthanlandmammalstosaveenergy.

C.Theyuseacombinationofphysiologicalandbehavioralstrategiestoregulatetemperature.

D.Thecounter-currentheatexchangerisineffectiveinwarmwater.

30.Insertsentence:"Thisphysiologicalversatilityallowsthemtoinhabitawiderangeofglobalclimates."

Wherewoulditbestfit?

A.Endofparagraph1.

B.Endofparagraph4.

C.Endofparagraph5.

D.Endofparagraph6.

ListeningSection

Conversation1

(ProfessorandStudent)

Professor:Hi,Sarah,youwantedtoseemeaboutyourtermpaper?

Student:Yes,ProfessorMiller.I’mplanningtowriteabouttheimpactofurbangreenspacesonmentalhealth.ButI’mhavingtroublenarrowingdownthespecificangle.

Professor:That’saveryrelevanttopic.Theissueisit'squitebroad.Areyoulookingatthepsychologicalbenefitsofgardening,orperhapstheeffectofparksoncommunitycohesion?

Student:Iwasthinkingmoreaboutthephysiologicalstressreduction.Youknow,howjustbeinginnaturelowerscortisollevels.

Professor:Okay,that'sasoliddirection.Butfora300-levelclass,weneedmorethanjustgeneralclaims.Youshouldprobablylookattheconceptof"biophilia."

Student:Biophilia?

Professor:Yes,E.O.Wilson’shypothesisthathumanshaveaninnatetendencytoseekconnectionswithnature.Youcouldframeyourpaperaroundhowurbandesignthatignoresthisleadstohigherstresslevels,whereasincorporatinggreenelements—evensmalloneslikestreettrees—mitigatesit.

Student:Thatsoundsinteresting.Icouldcomparetwoneighborhoodsinthecity,onewithhighgreendensityandonewithout.

Professor:Exactly.Butmakesureyoucontrolforothervariables,likesocioeconomicstatus.Youdon'twanttoattributestressreductionsolelytotreesifthewealthierneighborhoodalsohasbetteraccesstohealthcare.

Student:Right,that’sagoodpoint.I’lllookforstudiesthathaveattemptedtoisolatethevariableofgreenspace.

Professor:Great.Also,checkouttheworkbyRogerUlrich.Hedidthatfamousstudyonhospitalpatientsrecoveringfasterwhentheyhadaviewoftreesversusabrickwall.Itmightbeagoodcasestudyforyourintroduction.

Questions:

1.Whatisthemainpurposeoftheconversation?

A.Todiscussthestudent'sgradeonapreviousassignment.

B.Tohelpthestudentnarrowdownaresearchtopic.

C.Toexplaintheconceptofbiophiliatotheclass.

D.Toapprovethestudent'sthesisstatement.

2.Whatisthestudent'sinitialfocusforthepaper?

A.Communitycohesioninparks.

B.Theeconomicbenefitsofurbangardening.

C.Physiologicalstressreductioningreenspaces.

D.Thehistoryofurbanplanning.

3.WhydoestheprofessormentionE.O.Wilson?

A.Tosuggestatheoreticalframeworkforthepaper.

B.Tocorrectamisconceptionthestudenthas.

C.Torecommendaspecificbookforthebibliography.

D.Toexplainwhyurbanlivingisstressful.

4.Whatwarningdoestheprofessorgivethestudent?

A.Toavoidfocusingtoomuchonhospitalpatients.

B.Toensurethepaperisatleast20pageslong.

C.Tocontrolforvariableslikesocioeconomicstatus.

D.Tochooseatopicthathasmoreavailabledata.

5.Whatstudydoestheprofessorsuggestthestudentlookat?

A.Astudyontreeplantinginruralareas.

B.Astudyonhospitalrecoverytimesandviews.

C.Astudyoncortisollevelsinathletes.

D.Astudyonthecostofmaintainingparks.

Lecture1

(EnvironmentalScience-TheAlbedoEffect)

Professor:Todaywe'regoingtodiscusstheAlbedoEffect.Albedoisameasureofhowreflectiveasurfaceis.It’sexpressedasaratiobetween0and1.Asurfacewithanalbedoof0absorbsallsunlight,whileasurfaceof1reflectsallsunlight.Freshsnow,forexample,hasahighalbedo,around0.8to0.9,meaningitreflects80to90percentofincomingsolarenergy.Ontheotherhand,darkasphalthasalowalbedo,around0.05,absorbingalmostalltheheat.

Thisconceptiscriticalinunderstandingclimatechange,specificallythefeedbackloopsintheArctic.Astheglobalclimatewarms,seaiceintheArcticmelts.Thisexposesthedarkeroceanwaterbeneaththeice.Oceanwaterhasamuchloweralbedothanice.So,insteadofreflectingthesun'senergybackintospace,theoceanabsorbsit.Thisabsorbedheatwarmsthewaterfurther,whichinturnmeltsmoreice.Thisself-reinforcingcycleiscalledthe"ice-albedofeedbackloop."

It'snotjustanaturalphenomenon,though.Urbanareascreatetheirownmicroclimatesduetothe"Urbanheatislandeffect."Citiesarefullofdarksurfaceslikeroadsandrooftops,whichhavelowalbedosandabsorbheat.Tocombatthis,somecitiesareimplementing"coolroof"initiatives.Paintingroofswhiteorusingreflectivematerialsincreasestheiralbedo,reflectingmoresunlightandreducingtheneedforairconditioning.Studieshaveshownthatwidespreadimplementationofcoolroofscouldsignificantlylowerthepeaksummertemperaturesinlargecities.

However,alteringalbedocanhaveunintendedconsequences.Forexample,somegeoengineeringproposalshavesuggestedinjectingaerosolsintothestratospheretoincreasetheEarth'soverallalbedoandreflectsunlightawaytocooltheplanet.Whilethephysicsmightwork,thesideeffectsonweatherpatterns,likemonsoons,areunpredictableandpotentiallydangerous.

Questions:

6.Whatisthemaintopicofthelecture?

A.Thephysicsofsolarenergyabsorption.

B.ThedefinitionandimplicationsoftheAlbedoEffect.

C.Thehistoryofurbanplanninginhotclimates.

D.Geoengineeringsolutionstoglobalwarming.

7.Accordingtotheprofessor,howdoesfreshsnowaffecttheenvironment?

A.Itabsorbsheattomeltquickly.

B.Itreflectsmostofthesunlightthathitsit.

C.Ithasanalbedoofapproximately0.05.

D.Itcontributestotheurbanheatislandeffect.

8.WhydoestheprofessormentionoceanwaterinthecontextoftheArctic?

A.ToexplainwhytheArcticisgettingcolder.

B.Toillustratetheice-albedofeedbackloop.

C.Tocompareittothetemperatureofurbanasphalt.

D.Toshowthatwaterhasahigheralbedothanice.

9.Whatisthe"coolroof"initiativedesignedtodo?

A.Meltsnowfasteronrooftops.

B.Reducetheabsorptionofheatincities.

C.Usesolarpanelstogenerateelectricity.

D.Increasetheurbanheatislandeffect.

10.Whatdoestheprofessorimplyaboutgeoengineeringandaerosols?

A.Theyarethebestsolutiontoclimatechange.

B.Theyaretooexpensivetoimplement.

C.Theycouldhavenegativeeffectsonweatherpatterns.

D.Theyworkbyincreasingtheabsorptionofheat.

Conversation2

(StudentandLibrarian)

Student:Excuseme,I’mlookingforacopyof"TheEconomicHistoryofMedievalEurope."Theonlinecatalogsaysit'savailable,butIcan'tfinditontheshelf.

Librarian:Letmecheck.(Ty