2025年托福听力真题及答案解析

2025年托福听力真题及答案解析Part1Conversation1:AcademicAdvisingNarrator:Listentoaconversationbetweenastudentandanacademicadvisor.Student:Hi,ProfessorMiller.Thanksforseeingmeonsuchshortnotice.Iknowit’sregistrationweek,andyoumustbeswamped.Advisor:Hello,Sarah.Itisindeedabusytimeofyear,butIalwaystrytomakeroomformyadvisees.WhatcanIhelpyouwithtoday?Areyoureadytodiscussyourscheduleforthenextsemester?Student:Yes,mostly.I’vepickedoutmostofmyclassesforthespringsemester,butI’mrunningintoabitofaproblemwiththefinalrequirementformymajor.I’madoublemajorinHistoryandEnvironmentalScience,asyouknow.Advisor:Right,that’squiteaheavyworkload.Howareyoumanagingsofar?Student:It’sintense,butIloveit.TheissueiswiththeEnvironmentalSciencecapstoneproject.Ioriginallyplannedtodothe"UrbanEcology"track,whichrequirestheadvancedstatisticscourse,Eco-Stats302.ButwhenItriedtoregisterforit,IgotasystemerrorsayingIdidn'tmeettheprerequisite.Advisor:Letmepullupyourrecord...Ah,Isee.Thesystemshowsyouhaven'ttakenIntrotoBiostatistics,Eco-101.ButIthoughtyoutookthatlastyear?Student:Idid!Well,sortof.ItooktheequivalentcourseintheStatisticsdepartment,Stat-201.TheEnvironmentalSciencedepartmentsaidthatwouldcountasasubstitutewhenIdeclaredmymajor.Advisor:Irememberthatconversation.Itseemstheregistrar’sofficedidn'tupdatetheprerequisitechaininthecomputersystemtorecognizetheStatisticscourseasavalidsubstitutefortheEco-101requirement.Thathappenssometimeswithcross-listedcourses.Student:So,whatdoIdo?Eco-302isonlyofferedinthespring,andifIdon'ttakeitnow,Iwon'tbeabletograduateontimenextyear.Advisor:Don'tpanic.SinceIamthedepartmentchairforEnvironmentalScience,Icanissueamanualoverride.Icansignaformthatgrantsyoupermissiontoregisterfortheclassdespitethesystemerror.However,Ineedtobesureyouareprepared.Stat-201coversalotofprobabilitytheory,butEco-302focusesheavilyonregressionanalysisappliedtobiologicaldata.DidyourStat-201coursecoverregression?Student:Yes,wespentthelastmonthofthesemesteronlinearandmultipleregression.Iactuallydidaprojectusingcensusdata.Advisor:Excellent.Inthatcase,youaredefinitelyprepared.I’llsigntheoverrideformrightnow.You’llneedtotakeittotheregistrar’sofficeyourself,though.Student:Thatisahugerelief.Thankyousomuch!WhileI’mhere,thereisoneotherthing.Iwasthinkingaboutaddingaminor,butI’mworriedaboutthecreditlimit.Advisor:Wecandiscussthat,butlet’sgetyourmajorsortedoutfirst.Hereisthesignedform.Student:Thanks.Okay,abouttheminor...I’vereallyenjoyedtheHistoryofSciencecoursesI’vetakenformyHistorymajor.IwasthinkingaboutdoingaminorinPhilosophyofScience.Advisor:Thatfitsperfectlywithyourdoublemajor.Butyouarecurrentlyat18creditsfornextsemester.Addingaminorwouldrequirespecificelectives.Areyoutryingtofitoneinforthespring?Student:Iwaslookingat"PhilosophyofBiology."It’sonTuesdaysandThursdays.Advisor:That’sagreatcourse,butit’sa300-levelseminar.Itrequiresalotofreadingandwriting.Withthecapstoneprojectandthestatscourse,I’mhesitanttoapprove21credits.Itmightbetoomuch.Student:Isee.MaybeIcoulddroponeofmyHistoryelectives?I’mtaking"VictorianLiterature,"whichisinteresting,butnotstrictlynecessaryformymajorrequirements.Advisor:Ifyoudropthat,you’dbeat15creditsplustheseminar,so18total.Thatismuchmoremanageable.Butremember,youneedtofulfillthatHistoryelectivebeforeyougraduate.Couldyoutakeitoverthesummer?Student:Yes,summerschoolisanoption.Okay,soifIdropVictorianLitandaddthePhilosophyseminar,andyousigntheoverrideforStats,Ishouldbeset.Advisor:Thatsoundslikeasolidplan.I’llapprovethechangesonceyousubmitthemonline.Goodluck,Sarah!Questions:1.Whydoesthestudentgotoseetheacademicadvisor?A.TodeclareadoublemajorinHistoryandEnvironmentalScience.B.Toresolvearegistrationerrorforarequiredclass.C.TogetapprovalforaminorinPhilosophyofScience.D.Tocomplainaboutthedifficultyofthestatisticscourse.2.Whatcausedtheregistrationproblemforthestudent?A.Thestudentfailedtheprerequisitecourse.B.Theclasswasalreadyfull.C.Thecomputersystemdidnotrecognizeasubstitutecourse.D.Thestudentforgottopaytheregistrationfeeontime.3.WhatdoestheadvisorimplyaboutthecourseStat-201?A.ItisnotconsideredarigorousenoughcourseforEnvironmentalSciencemajors.B.Itdoesnotcoverregressionanalysis.C.Itisusuallyonlytakenbygraduatestudents.D.Itcoversthenecessarystatisticalconceptsforthecapstone.4.WhatdoestheadvisorsuggestthestudentdoregardingthePhilosophyofBiologycourse?A.Takeitinthefallsemesterinstead.B.DropaHistoryelectivetomakeroomforit.C.Takeitasapass/failcourse.D.Postponeituntilaftergraduation.5.Whatisthestudent'sfinalplan?A.KeepalloriginalclassesandaddthePhilosophycourse.B.DroptheStatisticscourseandtakeadifferentscienceelective.C.DropVictorianLiteratureandaddthePhilosophycourse.D.TaketheVictorianLiteraturecourseoverthesummerandkeepPhilosophy.Lecture1:ArtHistoryNarrator:ListentopartofalectureinanArtHistoryclass.Professor:Goodmorning,everyone.TodaywearegoingtocontinueourdiscussionoftheRenaissance,specificallyshiftingourfocustoNorthernEurope.WhileweoftenlooktoItaly—FlorenceandVenice—asthebirthplaceoftheRenaissance,theNorth,particularlytheFlandersregion(modern-dayBelgiumandtheNetherlands),developedadistinctstylethatranparalleltotheItalianRenaissance.Now,whenwetalkabout"NorthernRenaissanceArt,"wearetalkingaboutaperiodroughlyfromthe15thtothe16thcentury.OneofthemoststrikingdifferencesbetweentheNorthandItalywasthemedium.Italianartistsfavoredfresco—paintingonwetplaster—whichallowedthemtocoverlargewallsinchurchesandpalaces.However,thedampclimateintheNorthmadefrescopaintingimpractical;itsimplywouldn'tdryproperly.So,whatdidtheyturnto?Panelpainting.Specifically,oilpaintingonwoodpanels.Actually,theinventionofoilpaintingasweknowitisoftencreditedtoJanvanEyck,aFlemishartist.BeforevanEyck,temperapaintwascommon,butitdriedveryquickly,makingblendingcolorsandachievingsubtletransitionsinlightandshadowdifficult.VanEyckexperimentedwithmixingpigmentswithlinseedoil.Thisdriedslowly,whichallowedartiststobuilduplayersoftransparentglazes.Thistechniquecreatedanincredibledepthofcolorandalevelofrealism—especiallyintherenderingoftextures—thatwasunprecedented.Let’slookatperhapsthemostfamousworkbyJanvanEyck:"TheArnolfiniPortrait,"paintedin1434.ItdepictsawealthyItalianmerchant,GiovanniArnolfini,andhiswifeintheirhomeinBruges.Atfirstglance,itlookslikeasimplesnapshotofaweddingceremony.Butlookcloselyatthedetails.First,thetextureoftheclothes.Thefurtrimontheman'srobelookssosoftyoucouldtouchit.Thebrasschandelierreflectslightinawaythatfeelsmetallic.Butthemostfascinatingelementisthemirroronthebackwall.VanEyckpaintedthemirrorwithsuchprecisionthatwecanactuallyseethereflectionofthecouplefrombehind,aswellastwootherfiguresenteringtheroom—oneofwhomisbelievedtobetheartisthimself.Thisbringsustotheconceptof"disguisedsymbolism."UnlikeItalianart,wheresymbolismwasoftendrawnfromclassicalmythologyorgrandbiblicalnarratives,Northernarthidsymbolicmeaningsineverydaydomesticobjects.In"TheArnolfiniPortrait,"forexample,thesinglecandleburninginthechandeliersymbolizesthepresenceofGod,orperhapstheunityofmarriage.Thedogatthecouple'sfeetrepresentsfidelity—fido,faithfulness.Theorangesonthewindowsillmightsymbolizefertility.Whyhidethesesymbols?Well,somearthistoriansarguethatthesepaintingswerenotjustpublicdisplaysofwealth,butprivatedevotionalobjects.Thedetailedrealismwasn'tjustaboutshowingofftechnicalskill;itwasaboutrevealingthedivinepresencewithinthedomesticsphere.EveryobjectintheroomwasGod’screation,paintedwithreverence.AnotherkeyfigureisHieronymusBosch,whocameabitlater,inthelate15thandearly16thcenturies.Hisworkis...well,it’sstrange.WhilevanEyckfocusedonhyper-realism,Boschpaintedfantastical,oftennightmarishlandscapesfilledwithhybridcreatures.Hismostfamoustriptych,"TheGardenofEarthlyDelights,"isavisualsermonontheconsequencesofsinandtemptation.It’sastarkcontrasttotheorderly,piousdomesticityofvanEyck.So,tosummarize:TheNorthernRenaissancewascharacterizedbythemasteryofoilpaint,afascinationwithminutedetailsandtextures,andaformofsymbolismthatintegratedthespiritualintothematerialworld.WhiletheItalianswereobsessedwithhumananatomyandlinearperspectivetocreateperfect3Dspace,theNorthernerswereobsessedwiththesurfaceofthingsandthelightthatrevealedthem.Questions:6.Whatisthemainpurposeofthelecture?A.TocomparetheclimateofItalyandtheFlandersregion.B.ToexplainthetechnicalandthematiccharacteristicsofNorthernRenaissanceart.C.ToarguethatJanvanEyckwasabetterpainterthanLeonardodaVinci.D.TodiscussthereligiouscausesoftheProtestantReformation.7.Accordingtotheprofessor,whydidNorthernartistspreferoilpaintoverfresco?A.Oilpaintwascheapertoproducethantempera.B.Thedampclimatepreventedfrescofromdryingeffectively.C.PatronsintheNorthpreferredsmallerpaintingsthatcouldbehunginhomes.D.Oilpaintallowedforfastercompletionoflarge-scalecommissions.8.WhatadvantagedidoilpaintoffertoartistslikeJanvanEyck?A.Itallowedthemtopaintoncanvasinsteadofwood.B.Itdriedquickly,allowingformultiplelayersinasingleday.C.Itenabledsmoothblendingofcolorsandcreationofrealistictextures.D.Itwasmoredurableandresistanttofadingovertime.9.Inthediscussionof"TheArnolfiniPortrait,"whatdoestheprofessorimplyaboutthemirror?A.Itservesasasymbolofthewife'svanity.B.Itdemonstratestheartist'smasteryofperspectiveandreflection.C.Itwasacommonhouseholditemthathadnosymbolicmeaning.D.Itwasatechnicalerrorthatdistortedtheroom'sproportions.10.Whatis"disguisedsymbolism"asdescribedinthelecture?A.Usingmythologicalfigurestorepresentpoliticalleaders.B.HidingsecretmessagesinthepaintthatcanonlybeseenwithX-rays.C.Embeddingspiritualmeaningswithinordinary,everydayobjects.D.Creatingabstractartthatrepresentstheartist'sinternalemotions.11.HowdoestheprofessorcontrastJanvanEyckandHieronymusBosch?A.VanEyckpaintedreligiousscenes,whileBoschpaintedonlylandscapes.B.VanEyckfocusedonrealism,whileBoschfocusedonfantasticalimagery.C.VanEyckusedtempera,whileBoschinventedoilpainting.D.VanEyckwasfamousinItaly,whileBoschwasunknownoutsidetheNorth.Lecture2:ChemistryNarrator:ListentopartofalectureinaChemistryclass.Professor:Todaywe’regoingtodelveintoafundamentalconceptinchemicalkinetics:therateofreaction.Weallknowthatchemicalreactionsinvolvethebreakingandformingofbonds,buttheydon'tallhappenatthesamespeed.Some,likeanexplosion,happeninafractionofasecond.Others,liketherustingofiron,cantakeyears.So,whatgovernsthisspeed?Therateofareactionisessentiallythechangeinconcentrationofareactantorproductovertime.Wecanexpressthismathematically.Butthemoreinterestingquestionis:Howdowecontroltherate?Inindustry,ifyou'remanufacturingachemical,youusuallywantthereactiontogoasfastaspossibletomaximizeprofit.However,sometimesyouwanttoslowareactiondown,likethespoilageoffood.Thereareseveralfactorsthataffectreactionrates.Today,we'llfocusontemperatureandtheconceptofactivationenergy.Imagineahill.Ifyouwanttorollaballfromonesideofthehilltotheother,theballneedsenoughenergytogetoverthetopofthehillbeforeitcanrolldown.Inchemistry,this"hill"iscalledtheactivationenergybarrier.Reactantsareliketheballatthebottom;theypossessacertainamountofpotentialenergy.Totransformintoproducts,theymustcollidewithsufficientforce—sufficientkineticenergy—toovercomethisbarrier.ThisminimumenergyrequiredistheActivationEnergy,denotedas.Now,wheredoestemperaturecomein?Temperatureisameasureoftheaveragekineticenergyoftheparticlesinasubstance.Ifyouincreasethetemperature,theparticlesmovefaster.Thismeanstwothings:First,theparticlescollidemorefrequently.Second,andmoreimportantly,thecollisionsaremoreenergetic.Ahigherproportionofmoleculeswillhavekineticenergyequaltoorgreaterthantheactivationenergy.WecanquantifythisrelationshipusingtheArrheniusEquation.Thisequationdescribesthetemperaturedependenceofreactionrates.Itlookslikethis:kLet'sbreakthisdown.Here,kistherateconstant.Ahigherkmeansafasterreaction.Aisthefrequencyfactor,whichrelatestothefrequencyofcollisionsandtheorientationofthemolecules.eisthebaseofthenaturallogarithm.istheactivationenergy.Ristheuniversalgasconstant.AndTistheabsolutetemperatureinKelvin.Noticetheexponent:−.BecauseisalwayspositiveandRandTarepositive,theexponentisnegative.Thismeansthetermisalwayslessthan1.So,ifweincreasethetemperatureT,thedenominatorRTgetslarger.Thismakesthefractionsmaller.Consequently,thenegativeexponentbecomesasmallernegativenumber(closertozero).Thevalueoferaisedtoasmallernegativenumberbecomeslarger.Therefore,asTincreases,kincreases.Thismathematicalrelationshipperfectlyexplainsour"hill"analogy.Byraisingthetemperature,weareeffectivelygivingmoremoleculesthe"push"theyneedtogetovertheactivationenergyhill.However,temperatureisn'ttheonlywaytoovercometheactivationenergybarrier.Inmanybiologicalandindustrialprocesses,hightemperaturesarenotfeasible.Forinstance,ifwewantedtospeedupdigestioninthehumanbody,wecouldn'tjustraiseourbodytemperatureto100degreesCelsius;we'dcookourselves!Instead,livingorganismsusecatalystscalledenzymes.Acatalystprovidesanalternativepathwayforthereaction—onewithaloweractivationenergy.It’slikediggingatunnelthroughthehillinsteadofgoingoverit.Theballstillgetsfromonesidetotheother,butitdoesn'tneedasmuchenergytodoso.IntheArrheniusequation,addingacatalystlowers.Whendecreases,thefractiondecreases,theexponentbecomeslessnegative,andtherateconstantkincreases.Crucially,thecatalystitselfisnotconsumedinthereaction.Tosummarize,reactionratesdependheavilyontheenergyofthecollisions.Temperatureincreasestheenergyofthecollisions,whilecatalystslowertheenergybarrierrequiredforthereactiontoproceed.Questions:12.Whatisthemaintopicofthelecture?A.Theprocessofrustingiron.B.Thefactorsinfluencingtherateofchemicalreactions.C.Howtocalculatetheuniversalgasconstant.D.Thedifferencebetweenproductsandreactants.13.Accordingtotheprofessor,whyisactivationenergycomparedtoahill?A.Toillustratethatreactionsrequireenergyinputtoproceed.B.Toshowthatreactionsalwaysreleaseenergy.C.Toexplainwhysomereactionsarereversible.D.Todemonstratethattemperaturehasnoeffectonsolidreactions.14.IntheArrheniusequation,whatdoesthevariablekrepresent?A.Theactivationenergy.B.Theabsolutetemperature.C.Therateconstant.D.Thefrequencyfactor.15.HowdoesanincreaseintemperatureaffectthevalueofkintheArrheniusequation?A.Itdecreaseskbecausetheexponentbecomesmorenegative.B.IthasnoeffectonkbecauseRisaconstant.C.Itincreaseskbecausetheexponentbecomeslessnegative.D.Itincreaseskbyincreasingthevalueof.16.Whydoestheprofessormentiondigestioninthehumanbody?A.Togiveanexampleofareactionthatrequireshightemperatures.B.Toillustrateasituationwhereacatalystisnecessaryinsteadofhighheat.C.Toexplainthatenzymesaredestroyedbyhightemperatures.D.Toshowthatbiologicalreactionsareslowerthanindustrialones.17.Howdoesacatalystaffectachemicalreaction?A.Itincreasesthetemperatureofthereaction.B.Itincreasesthefrequencyofcollisionsbetweenmolecules.C.Itlowerstheactivationenergyrequiredforthereaction.D.Itchangestheproductsofthereaction.Part2Conversation2:ServiceEncounterNarrator:Listentoaconversationbetweenastudentandauniversityemployee.Student:Excuseme.IwastoldIcouldpickupmystudentIDhere.Ilostmyoldoneoverthebreak,andIneedareplacementtogetintomydormandthelibrary.Employee:Certainly.Icanhelpyouwiththat.You’llneedtofilloutthisreplacementform.It’sfivedollarsforastandardreplacement.Student:Okay,noproblem.Iactuallyhaveaquestion,though.MyroommatetoldmethattheIDsarebeingupgradedthissemester.Somethingaboutanewchip?ShouldIwaitforthat,orwillthisonebethenewversion?Employee:Ah,yes.Theuniversityisrollingoutthenew"SmartIDs"startingthisweek.TheyhaveanintegratedchipthatallowsyoutouseyourIDasadebitcardatthecampusbookstoreandthevendingmachines,anditalsohasabuilt-inbuspassforthecitytransitsystem.Student:Thatsoundsreallyuseful.WillIgetoneofthose?Employee:Sinceyouaregettingareplacement,youwillautomaticallybeissuedthenewSmartID.There’sactuallynoextrachargefortheupgradeitself,justthestandardfive-dollarreplacementfee.Student:That’sgreat.DoIneedtodoanythingspecialtoactivatethedebitcardfeature?Employee:Yes.You’llneedtolinkittoyourstudentaccountorabankaccount.Thereareinstructionsonthebackofthecard,buttheeasiestwayistogotothestudentportalonline.Onceyoulogin,there’satabfor"CampusCardServices."Youcandepositmoneytheredirectlyfromacreditcardorcheckingaccount.Student:Perfect.Iassumemyoldcard’saccesswillbedisabledimmediately?Employee:Itshouldbealready.Whendidyoureportitlost?Student:Icalledcampussecurityyesterday.Employee:Thenyou’reallset.Thesystemblockstheoldcardnumberassoonasit’sreported.Justtobesafe,I’lldouble-checkthedatabase...Okay,yes,youroldcardisflaggedaslost.Soifanyonefindsit,theywon’tbeabletouseit.Student:That’sarelief.Isthephotothesameasmyoldone?Employee:Wekeepdigitalrecordsofallstudentphotos.We’llusetheonefromyourfreshmanyearunlessyou’vehadasignificantchangeinappearanceoryouwanttoupdateit.Student:I’velostsomeweightandgotglassessincethen.Itdoesn'treallylooklikemeanymore.Employee:Inthatcase,wecantakeanewphotorightnow.There’sacamerastationjustoverthereagainstthewall.Goaheadandstandinfrontofit.Student:Okay.[Soundofmovingaway,thenreturning].Didittake?Employee:Yes,thatlooksgood.Muchbetterlikeness.Okay,I’mprocessingthecardnow.Itwilljusttakeamomenttoprint...Hereyougo.Student:Thanks!So,aboutthebuspassfeature.Isthatactiveimmediately?Employee:Thebuildingaccessandlibraryfunctionsareactiveimmediately.Thebuspassintegrationtakesabout24hourstosyncwiththecitytransitsystem.Soyouwon’tbeabletoridethecitybusforfreeuntiltomorrowmorning.Butthedebitcardfeatureworksassoonasyouaddfundstoyouraccountonline.Student:Gotit.Thanksforyourhelp.Employee:You’rewelcome.Haveagoodsemester.Questions:18.WhydoesthestudentvisittheIDoffice?A.Tolinkhisbankaccounttotheuniversity.B.TogetareplacementforalostIDcard.C.Toaskaboutthebuspasssystem.D.Toupdatehisphotofortheyearbook.19.WhatfeatureofthenewSmartIDdoestheemployeemention?A.Itcanbeusedtoopenoff-campusapartments.B.Itfunctionsasadebitcardandbuspass.C.IthasGPStrackingforsecurity.D.Itallowsstudentstoskiplinesatthecafeteria.20.Whatdoesthestudentsayabouthisappearance?A.Hehasgrowntaller.B.Hehasdyedhishair.C.Hehaslostweightandwearsglasses.D.Helooksolderthanhisfreshmanphoto.21.Whatindicatesthatthestudent’soldcardisnolongerusable?A.Thestudentreporteditlostthepreviousday.B.Thestudentfoundthecardinhisdormroom.C.Thenewcardhasadifferentnumber.D.Thesemesterhasnotstartedyet.22.Whenwillthestudentbeabletousethebuspassfeature?A.Immediately.B.After24hours.C.Onceheaddsfundstotheaccount.D.Afterheregistershisclasses.Lecture3:EnvironmentalScienceNarrator:ListentopartofalectureinanEnvironmentalScienceclass.Professor:Overthepastfewweeks,we'vebeendiscussingthecarboncycleandtheroleofforestsascarbonsinks.Today,Iwanttoturnourattentiontotheoceans.Theoceanisthelargestactivecarbonsinkontheplanet.Itabsorbsabout30%ofthecarbondioxide(C)releasedbyhumanactivity.Buthowdoesitwork?It’snotjustlikeaspongesoakingupwater.It’sacomplexphysico-chemicalprocess.Thefirststepisasimplegasexchangeatthesurface.Cintheatmospheredissolvesintothesurfacewater.ThisisgovernedbyHenry'sLaw,whichbasicallystatesthattheamountofgasthatdissolvesinaliquidisproportionaltothepartialpressureofthatgasabovetheliquid.So,asatmosphericClevelsrise,theoceanabsorbsmore.However,oncetheCisinthewater,itreactswithwatermoleculestoformcarbonicacid.Thisisthecrucialpart.Carbonicacidthendissociatesintobicarbonateandcarbonateions,releasinghydrogenions()intheprocess.Thisincreaseinhydrogenionsiswhatwecalloceanacidification.Theocean'spHisdropping,makingitmoreacidic.Now,whyisthisaproblem?Manymarineorganisms,suchascorals,shellfish,andsometypesofplankton,buildtheirshellsandskeletonsfromcalciumcarbonate(CaButthereisanotherplayerinthissystemthatweusedtoignore:Zooplankton.Specifically,atypecalled"pteropods,"orseabutterflies.Theyaretinysnailsthatswiminthewatercolumn.RecentresearchintheSouthernOceanhasshownthattheshellsofpteropodsarealreadyshowingsignsofdissolutionduetoacidification.Whydoesthismatter?Pteropodsareakeyfoodsourceforlargerfishlikesalmonandmackerel,andevenforwhalesinsomeregions.Ifthebaseofthefoodwebstartstocrumble—literally—theentireecosystemcouldbeatrisk.However,theoceandoeshaveabufferingcapacity,awaytofightbackagainstacidification.Thisinvolvesthedissolutionofcalciumcarbonatesedimentsontheseafloor.Asthewaterbecomesmoreacidic,itcandissolvetheseancientcarbonatedepositsontheoceanfloor.Thisdissolutionreleasescarbonateionsbackintothewater,whichneutralizessomeoftheacid.Butthisprocessisextremelyslow.Ittakesthousandsofyearsforthisnaturalbuffertoreacttotherapidchangesweareseeingnow.WearepumpingCintotheatmosphereataratethatthegeologicalchemistryoftheoceansimplycannotkeepupwith.So,wehaveadoublewhammy:surfacewatersareacidifyingquickly,harmingmarinelife,andthedeepocean'sabilitytobufferthischangeistooslowtohelpusintherelevanttimeframe.Thisunderscorestheurgencyofreducingemissions—notjusttomitigatewarming,buttosavethechemistryoftheoceanitself.Questions:23.Whatisthemainpurposeofthelecture?A.Todescribetheprocessofoceanacidificationanditsbiologicalimpacts.B.ToexplainhowtomeasurethepHlevelsoftheocean.C.Tocomparethecarbonabsorptionratesofdifferentoceans.D.Todiscussthemigrationpatternsofpteropods.24.Accordingtotheprofessor,howdoesCentertheoceanwater?A.Throughthedecompositionofmarinelife.B.Bydissolvingdirectlyfromtheatmosphereintothesurfacewater.C.Throughvolcanicactivityontheseafloor.D.Bybeingsecretedbyphytoplankton.25.Howdoestheprofessorexplaintheformationofcarbonicacid?A.Creactswithcalciumcarbonatetoformcarbonicacid.B.Creactswithwatermoleculestoformcarbonicacid.C.Hydrogenionscombinewithcarbonatetoformcarbonicacid.D.Bicarbonateionsbreakdowntoformcarbonicacid.26.Whydoestheprofessormentioncoralsandshellfish?A.Togiveexamplesoforganismsthatareresistanttoacidification.B.Toillustratetheimpactoflowcarbonateionconcentrationonmarinelife.C.ToshowthattheseorganismsproducetoomuchC.D.Toexplainhowtheycontributetotheocean'sbufferingcapacity.27.Whatdoestheprofessorimplyaboutpteropods?A.Theyareaprimaryproducerofoxygenintheocean.B.TheyarenotsignificantlyaffectedbypHchanges.C.Theyareacrucialfoodsourceforlargermarineanimals.D.Theyliveontheseaflooranddissolvecarbonatesediments.28.Whatistheocean'snaturalbufferingmechanismagainstacidification?A.Therapidreproductionofphytoplankton.B.TheabsorptionofCbyseaice.C.Thedissolutionofcalciumcarbonatesedimentsontheseafloor.D.Theconversionofacidintooxygenbydeep-seavents.Lecture4:AnthropologyNarrator:ListentopartofalectureinanAnthropologyclass.Professor:Todaywe’regoingtodiscussthedomesticationofthedog.It’satopicthatoftensparksdebatebecauseithappenedsolongago—thousandsofyearsbeforetheinventionofwriting—sowedon'thavewrittenrecordstotellusexactlyhowithappened.Wehavetorelyonarchaeologyandgenetics.Thetraditionalview,the"cooperationhypothesis,"suggeststhathumansadoptedwolfpups.Perhapsancienthuntersfoundadenofwolfpups,tookthecuteoneshome,andraisedthem.Overgenerations,thesewolvesbecametamerandevolvedintodogs.Inthisscenario,humanstooktheactivestep;itwasahuman-initiatedprocess.However,thereisacompetingtheorythathasgainedalotoftractioninrecentyears:the"self-domesti