2026年4月托福真题及答案

2026年4月托福真题及答案

ReadingSection

Passage1

ThereintroductionoftheNorthAmericanbeaver(Castorcanadensis)toecosystemswheretheyhadbeenextirpatedhassparkedsignificantdebateamongecologists,hydrologists,andlandmanagers.Whilehistoricallyviewedasanuisanceduetotheirtree-fellingactivitiesanddamconstruction,contemporaryecologicalperspectiveshaveshiftedtowardsrecognizingbeaversas"ecosystemengineers."Thischangeinstanceisdrivenbyagrowingbodyofevidencesuggestingthatbeaver-mediatedlandscapealterationscanenhancebiodiversity,improvewaterquality,andincreaseecosystemresiliencetoclimatechange.

Oneoftheprimarybenefitsofbeaveractivityisthecreationofwetlands.Bybuildingdams,beaversraisewatertables,transformingflowingstreamsintoseriesofpondsandmarshes.Theseaquaticenvironmentsserveascriticalhabitatsforaplethoraofspecies,includingamphibians,waterfowl,andfish.Forinstance,theslow-movingwaterbehindbeaverdamsprovidesidealspawninggroundsfortroutandsalmon,protectingeggsfrombeingwashedawayduringhigh-flowevents.Furthermore,theincreasedvegetationcomplexityinthesezonesoffersshelterandbreedingsitesforsongbirdsandinsects,therebyamplifyingtheoverallspeciesrichnessofthearea.

Inadditiontosupportingbiodiversity,beaverdamsfunctionasnaturalfiltrationsystems.Aswaterpercolatesthroughtheporousstructureofthedamandtheassociatedsediment,suspendedsolidsandpollutantssuchasnitrogenandphosphorusaretrapped.Thisprocess,knownasnutrientretention,mitigatestheimpactsofagriculturalrunoff,reducingthelikelihoodofeutrophicationdownstream.Studieshaveshownthatstretchesofriverwithactivebeavercomplexescontainsignificantlyhigherconcentrationsoforganiccarbonandlowerlevelsofnitratescomparedtofree-flowingsections.Consequently,beaversplayapivotalroleinmaintainingthechemicalbalanceoffreshwatersystems.

However,theecologicalengineeringperformedbybeaversisnotwithoutconflict,particularlyinhuman-dominatedlandscapes.Theinundationofagriculturalland,timberresources,andinfrastructure(suchasroadsandrailways)posessubstantialeconomicchallenges.Whenbeaversdamculverts,theycancausefloodingthatdamagespropertyanddisruptstransportationnetworks.Traditionalmanagementstrategieshaveoftenfocusedonlethalremovalordestructionofdams.Yet,thesemethodsarefrequentlytemporary,asnewbeaversoftenrecolonizethevacanthabitat.

Toaddresstheseconflicts,flowdevices—oftenreferredtoas"beaverdeceivers"—havebeendeveloped.Thesesystemsconsistofpipesinstalledthroughbeaverdamsthatregulatewaterlevelswithoutalertingthebeaverstotheleak.Bymaintainingthewaterlevelbelowthethresholdofflooding,flowdevicesallowbeaversandhumanstocoexist.Researchindicatesthatthesenon-lethalmanagementtechniquesarenotonlymorecost-effectiveinthelongrunbutalsopreservetheecologicalbenefitsderivedfromthebeaverwetlands.Asclimatechangeexacerbatesdroughtsandfloods,thecapacityofbeaverstostorewaterandattenuatefloodpeaksmaybecomeanincreasinglyvaluableecosystemservice,necessitatingashifttowardsmoreintegratedandadaptivemanagementapproaches.

Questions:

1.Theword"extirpated"inparagraph1isclosestinmeaningto:

A.Indigenous

B.Eradicated

C.Endangered

D.Domesticated

2.Accordingtoparagraph2,howdobeaverdamsbenefitfishpopulations?

A.Byincreasingthewatertemperature

B.Bypreventingeggsfrombeingsweptaway

C.Byreducingthenumberofpredatorybirds

D.Byincreasingtheflowrateoftheriver

3.Thephrase"plethoraof"inparagraph2suggeststhat:

A.Thenumberofspeciesislimited

B.Thespeciesaredangerous

C.Thereisanoverabundanceofspecies

D.Thereisadiversemixofspecies

4.Accordingtoparagraph3,whyarebeaverdamsconsideredeffectivefiltrationsystems?

A.Theyblocktheflowofwatercompletely

B.Theytrapsedimentsandnutrients

C.Theyaddchemicalstothewater

D.Theyincreasethespeedofwaterflow

5.Theword"mitigates"inparagraph3isclosestinmeaningto:

A.Worsens

B.Intensifies

C.Lessens

D.Monitors

6.Whichofthefollowingismentionedinparagraph4asanegativeimpactofbeavers?

A.Decreaseinlocalbiodiversity

B.Increasedriskofforestfires

C.Floodingofagriculturalland

D.Contaminationofdrinkingwater

7.Whydoestheauthormention"lethalremoval"inparagraph4?

A.Toadvocateforitsuse

B.Toexplainwhyitistheonlysolution

C.Tocontrastitwithnon-lethalmethodslikeflowdevices

D.Toshowthatbeaversarebecomingextinct

8.Howdo"beaverdeceivers"work?

A.Theyscarebeaversawayfromthearea

B.Theychemicallydissolvethedams

C.Theyregulatewaterlevelswithoutthebeaversnoticing

D.Theyrelocatebeaverstosaferhabitats

9.Theauthor'sattitudetowardsbeaversinthefinalparagraphcanbestbedescribedas:

A.Critical

B.Ambivalent

C.Supportiveoftheirecologicalrole

D.Indifferent

10.Whatcanbeinferredaboutthefutureofbeavermanagement?

A.Lethalremovalwillbecomethestandard

B.Beaverswilllikelybeignored

C.Theirroleinclimateresiliencemayleadtobettercoexistencestrategies

D.Beaverpopulationswilldecreasenaturally

Passage2

ThetransitionfromtheMiddleAgestotheRenaissanceinEuropewasnotmerelyarediscoveryofclassicalantiquitybutaprofoundtransformationintheeconomicstructuresthatunderpinnedsociety.Whilemuchattentionislavishedontheartisticandphilosophicalachievementsoftheperiod,theeconomicenginedrivingthesechangeswastheshiftfromafeudal,land-basedeconomytooneincreasinglydominatedbymercantilecapitalismandurbancenters.Thisshiftwascatalyzedbyaseriesofdemographicshocks,technologicalinnovations,andchangingsocialattitudestowardswealthandtrade.

TheBlackDeath,whichravagedEuropeinthe14thcentury,servesasastarkturningpoint.Theunprecedentedlossoflife—estimatedatbetweenone-thirdandone-halfofthepopulation—createdaseverelaborshortage.Intherigidfeudalsystem,peasantswereboundtothelandandobligatedtoworkfornoblesinexchangeforprotection.However,withthescarcityoflabor,thesurvivingpeasantryfoundthemselvesinapositiontonegotiate.Lords,desperatetokeeptheirlandsproductive,wereoftenforcedtoofferbetterwages,lowerrents,orevenfreedom.Thiserosionofthemanorialsystemliberatedasignificantportionoftheworkforce,allowingthemtomigratetocitiesorspecializeincraftproduction.

Simultaneously,theresurgenceoflong-distancetradeplayedacrucialrole.TheCrusades,whilemilitarilydubiousforEurope,hadreopenedtraderoutestotheEast,exposingEuropeanmarketstospices,silks,andotherluxurygoods.Thisdemandincentivizedthedevelopmentofamerchantclassdistinctfromthelandedaristocracy.CitieslikeVenice,Genoa,andlaterBrugesandAntwerp,grewwealthyashubsofcommerce.Theseurbancentersbecamehotbedsfortheaccumulationofcapital,whichcouldthenbeinvestedintheartsandsciences.Thepatronagesystem,famouslyexemplifiedbytheMedicifamilyinFlorence,wasadirectresultofthissurpluswealth.Merchantsandbankerssoughttolegitimizetheirstatusbyfundingpublicworks,cathedrals,andtheworksofartistslikeMichelangeloandLeonardodaVinci.

Technologicaladvancementsalsofacilitatedthiseconomicmetamorphosis.Theintroductionoftheheavyplowandthethree-fieldsysteminagriculturehadalreadyincreasedproductivitypriortotheplague,butthepost-plagueperiodsawinnovationsinmanufacturingandfinance.Thefullingmill,poweredbywater,mechanizedtheclothindustry,whichwasthebackboneofthemedievalEuropeaneconomy.Moresignificantly,thedevelopmentofdouble-entrybookkeepingandtheriseofbankinghousesallowedformorecomplexfinancialtransactions.Theabilitytoborrowandlendlargesumsofmoneyenabledmerchantstofundexpeditionsandtakerisksthatwerepreviouslyimpossible,layingthegroundworkfortheageofexploration.

However,thiseconomicexpansionwasnotwithoutitsdiscontents.TheinfluxofgoldandsilverfromtheNewWorldinthe16thcenturyledtoinflation,knownasthe"PriceRevolution,"whicherodedthefixedincomesofthenobilityandthelowerclassesalike.Furthermore,thegrowthofcitiesoftenledtosqualidlivingconditionsandthespreadofdisease.Theconsolidationofwealthinthehandsofafewmerchantprincescreatedawideninggapbetweentherichandthepoor,challengingthecommunalethosofthemedievalperiod.Despitethesechallenges,thefundamentalshifttowardsaneconomybasedoncapital,trade,andlabormobilitywasirreversible,settingthestageforthemodernindustrialworld.

Questions:

1.Theprimarypurposeofthispassageisto:

A.DiscusstheartisticachievementsoftheRenaissance

B.AnalyzetheeconomicfactorsthatfacilitatedthetransitionfromtheMiddleAgestotheRenaissance

C.CriticizetheimpactoftheBlackDeathonEuropeansociety

D.DescribethemilitaryhistoryoftheCrusades

2.Accordingtoparagraph2,howdidtheBlackDeathaffectthefeudalsystem?

A.Itstrengthenedthepowerofthenobles

B.Itcausedalaborshortagethatempoweredpeasants

C.Itledtothetotalcollapseofagriculture

D.Itencouragednoblestoinvadeneighboringlands

3.Theword"catalyzed"inparagraph1isclosestinmeaningto:

A.Hindered

B.Accelerated

C.Observed

D.beautified

4.WhydoestheauthormentiontheMedicifamilyinparagraph3?

A.Toillustratethelinkbetweeneconomicwealthandartisticpatronage

B.Toshowhowtheylosttheirfortune

C.Tocomparethemtothenobility

D.Toexplainthefailureofthebankingsystem

5.Accordingtoparagraph4,whatwasthesignificanceofdouble-entrybookkeeping?

A.Itallowedformorecomplexfinancialtransactions

B.ItwasinventedbyLeonardodaVinci

C.ItpreventedthePriceRevolution

D.Itmadefarmingmoreefficient

6.Theword"metamorphosis"inparagraph4refersto:

A.Abiologicalchangeininsects

B.Apoliticalrevolution

C.Atransformationoftheeconomicstructure

D.Areligiousreform

7.Whatwasthe"PriceRevolution"mentionedinparagraph5?

A.Adropinthepriceofgoodsduetosurplus

B.Inflationcausedbytheinfluxofgoldandsilver

C.Agovernmentpolicytocontrolprices

D.Aneconomicboombasedontrade

8.WhichofthefollowingisNOTmentionedasaresultoftheeconomicexpansion?

A.Wideninggapbetweenrichandpoor

B.Improvedlivingconditionsforallcitydwellers

C.Inflation

D.Investmentinthearts

9.ThepassagesuggeststhattheCrusades:

A.WereacompletefailureforEurope

B.Primarilyservedtospreadreligion

C.IndirectlystimulatedEuropeantrade

D.Endedthefeudalsystemimmediately

10.Whatcanbeinferredabouttherelationshipbetweenthenobilityandthemerchantclass?

A.Theywerealwaysinviolentconflict

B.Themerchantclasseventuallychallengedthetraditionalstatusofthenobility

C.Thenobilityweretheprimaryinventorsofnewtechnologies

D.Themerchantclasswerestrictlyfarmers

Passage3

Geology:TheMantlePlumeHypothesis

Fordecades,thetheoryofplatetectonicshasprovidedarobustframeworkforunderstandingthemovementofEarth'slithosphericplates.However,platetectonicsalonecannotfullyexplaintheoccurrenceofcertainvolcanicphenomena,particularly"hotspots"—regionsofintensevolcanismfixedrelativetothemovingplatesabovethem,suchastheHawaiianIslands.Toaccountfortheseanomalies,geophysicistsproposedtheMantlePlumeHypothesis.Thistheorysuggeststhatnarrow,columnarupwellingsofabnormallyhotrockoriginateatthecore-mantleboundary,roughly2,900kilometersbeneaththesurface,andrisethroughthemantletothecrust.

Themechanicsofamantleplumearedrivenbythermalbuoyancy.Thecore-mantleboundaryisaregionofextremetemperaturecontrast.Heatfromtheoutercoreconductsintothebaseofthemantle,creatingathermalboundarylayer.Whenthislayerbecomessufficientlythickandunstable,ablobofhotmaterialdetachesandbeginstoascend.Asitrises,pressuredecreases,causingtheplumematerialtomeltpartiallyanddecompress.Thisgenerateslargevolumesofmagma.Whentheplumeheadimpingesonthebaseofthelithosphere,itspreadslaterally,causingwidespreadupliftandmassivevolcaniceruptionsknownasfloodbasalts.Thisinitialphaseisoftenfollowedbyalong,steadytailofupwelling,whichcreatesatrackofsmallervolcanoesasthetectonicplatemovesoverthestationaryplume.

Oneofthestrongestlinesofevidenceformantleplumesistheageprogressionofislandchains.IntheHawaiian-Emperorchain,theislandsbecomeprogressivelyoldertothenorthwest.TheBigIslandofHawaii,currentlysituatedoverthehotspot,isactive,whiletheislandstothenorthwestareextinctanderoded.Thislineartrendfitsthemodelofastationaryheatsourcepuncturingamovingplate.Bycalculatingtherateofmovement(thespeedofthePacificPlate)andthedistancebetweenislands,scientistscanestimatetheageofthevolcanicactivity,whichcorrelateswellwithradiometricdating.

However,theMantlePlumeHypothesisisnotwithoutitscritics.Somegeophysicistsarguethattheseismicimagingofthemantleisnotclearenoughtodefinitivelyprovetheexistenceofdeep,narrowplumesconnectingthecoretothesurface.Alternativemodels,suchasthe"platehypothesis,"suggestthathotspotscanbeexplainedbyshallowupper-mantleprocesses,suchassmall-scaleconvectionorcracksinthelithospherethatallowmelttoescapefromtheasthenosphere.Thesecriticspointoutthatsomeproposedhotspotsdonotexhibitclearageprogressionsorfixedpositionsrelativetooneanother.

Furthermore,recenthigh-resolutionseismictomographyhasyieldedcomplexresults.Whilesomeimagesshowfaint,low-velocityzonesextendingdeepintothemantlebeneathhotspotslikeHawaiiandIceland,othersshowstructuresthatappeartoberootedatshallowerdepths.Thishasledtoanuancedviewwhere"plumes"mightexistinvariousforms—somedeepandclassic,othersshallowandtransient.Despitetheongoingdebate,theconceptofmantleplumesremainsacentralparadigmingeodynamics,offeringaplausibleexplanationfortheplanet'sinternalheattransportandthedistributionofvolcanicislandsawayfromplateboundaries.

Questions:

1.Whatisthemaintopicofthepassage?

A.Themovementoftectonicplates

B.ThehistoryoftheHawaiianIslands

C.TheMantlePlumeHypothesisanditsevidence

D.ThecompositionoftheEarth'score

2.Accordingtoparagraph2,whatcausestheplumematerialtomeltasitrises?

A.Contactwithwater

B.Increaseinpressure

C.Decreaseinpressure(decompression)

D.Chemicalreactionswiththecrust

3.Theword"impinges"inparagraph2isclosestinmeaningto:

A.Separates

B.Strikes

C.Creates

D.Destroys

4.HowdoestheHawaiian-EmperorchainsupporttheMantlePlumeHypothesis?

A.Theislandsareallthesameage

B.Theislandsgetyoungerinthedirectionofplatemovement

C.Theislandsarearrangedinacircularpattern

D.Theislandsarecomposedofdifferentrocktypes

5.Whydosomescientistssupportthe"platehypothesis"?

A.Theybelievemantleplumesaretoohot

B.Seismicimagingdoesnotclearlyshowdeepplumes

C.Theydenytheexistenceofvolcanoes

D.Thecore-mantleboundaryistoocold

6.Theword"anomalies"inparagraph1refersto:

A.Standardfeaturesofplatetectonics

B.Deviationsfromtheexpectedpattern

C.Errorsinscientificmeasurement

D.Commonvolcanicrocks

7.Whatis"floodbasalt"?

A.Alargeamountofwaterreleasedfromthemantle

B.Massivevolcaniceruptionscausedbytheplumehead

C.Atypeofearthquake

D.Thesteadytailoftheplume

8.Accordingtoparagraph5,whathasrecentseismictomographyrevealed?

A.Definitiveproofthatallplumesaredeep

B.Thatthehypothesisiscompletelywrong

C.Thatplumestructuresmayvaryindepthandform

D.ThattheEarth'scoreisliquid

9.Theauthor'stoneinthefinalparagraphisbestdescribedas:

A.Highlyskeptical

B.Dogmatic

C.Balancedandobjective

D.Enthusiastic

10.Whichofthefollowingistrueaboutthe"tail"ofamantleplume?

A.Itcausestheinitialmassiveeruption

B.Itcreatesatrackofsmallervolcanoes

C.Itishotterthanthehead

D.Itmoveshorizontally

ListeningSection

Conversation1

(Professorspeakingwithastudentaboutaninternship)

Professor:HiSarah,comein.YoumentionedinyouremailthatyouwantedtodiscusstheinternshiprequirementfortheEnvironmentalSciencedegree?

Student:Yes,ProfessorMiller.IfoundalistingforapositionattheGreenValleyWaterTreatmentPlant.Itlooksreallyinteresting,butI’mworrieditmightnotfulfillthe"researchcomponent"requirement.

Professor:Letmesee.(Looksatscreen)GreenValley...Theyfocusonfiltrationandwastemanagement,correct?

Student:Exactly.Theywantmetoassistwithmonitoringtheefficiencyoftheirnewsandfilters.Itinvolvescollectingwatersamplesandanalyzingturbiditylevels.

Professor:Thatsoundspromising.Therequirementisthatyouengageinsystematicinvestigationtocontributetoaproject.Itdoesn'tstrictlyhavetobeacademicresearchinalab.Ifyouarecollectingdatatooptimizetheirsystem,thatcountsasappliedresearch.

Student:That’sarelief.ButIalsoneedafacultysupervisor.Wouldyoubewillingtosignoffonmyhoursandreports?

Professor:Icancertainlydothat,providedyousubmitaweeklysummaryofyourdataandafinalpaperanalyzingtheimplicationsofyourfindingsforthecourse.

Student:Icandefinitelydothat.Thereisonecatchthough—theinternshipisunpaid,anditrequires20hoursaweek.IwaswonderingifIcouldgetcoursecreditforitinsteadoftakingtheelective?

Professor:Typically,internshipsareadditionaltoyourcoursework.However,ifthisisafullsemestercommitmentandtheworkisrigorousenough,wemightbeabletosubstituteitforyour"FieldMethods"elective.I’llneedtoapproveyourlearningobjectivesfirst.

Student:Okay,I’lldraftthoseupandbringthemtoournextmeeting.

Professor:Perfect.Makesuretoemphasizetheanalyticalskillsyou'llbeusing.

Question1:Whyisthestudentvisitingtheprofessor?

Question2:Whatisthestudent'smainconcernabouttheinternship?

Question3:Whatdoestheprofessorimplyaboutthe"researchcomponent"?

Question4:Whatdoestheprofessorrequirethestudenttosubmit?

Question5:Whatcanbeinferredaboutthe"FieldMethods"elective?

Lecture1:Biology-MimicryinNature

Professor:Today,we'regoingtotalkaboutmimicry.Mimicryiswhenanorganismevolvestoresembleanotherobjectororganism.Thereareseveraltypes,butthemostfamousisBatesianmimicry.Thisiswhereaharmlessspeciesmimicsthewarningsignalsofaharmfulspeciestodeterpredators.Forexample,theViceroybutterflylooksstrikinglysimilartotheMonarchbutterfly.Monarchsaretoxictobirdsbecausetheyeatmilkweedcontainingcardenolides.BirdslearntoavoidthebrightorangepatternoftheMonarch.TheViceroy,whichispalatable,exploitsthisbylookingthesame.

However,recentstudiessuggesttherelationshipmightbemorecomplex.ItturnsouttheViceroyisalsosomewhatunpalatable,justlesssothantheMonarch.ThisleadstoaphenomenoncalledMüllerianmimicry,wheretwoormoreharmfulspeciesresembleeachother.Bysharingthesamewarningpattern,theyreinforcethepredator'savoidancebehavior.Itreducesthemortalityrateforbothspeciesbecausethepredatoronlyhastolearnonepattern.

Anotherformisaggressivemimicry.Here,apredatororparasitemimicssomethingharmlesstolureitsprey.Theanglerfishisaclassicexample.Ithasadorsalspinethatlookslikeasmallworm.Itwigglesthisappendagetoattractsmallerfish.Whentheygetclose,theanglerfishsnapsthemup.So,whileBatesianandMüllerianmimicryaredefensive,aggressivemimicryisoffensive.

Wecanalsoseethisintheinsectworldwiththebolasspider.Thisspidermimicsthepheromonesoffemalemothstoattractmalemoths.Whenthemalemotharrivesexpectingamate,itgetscapturedinstead.Thisisachemicalratherthanvisualmimicry.Theprecisionofthisevolutionaryadaptationisastounding,asthespidercanadjustthepheromoneblendtomatchdifferentmothspeciesactiveduringdifferentnights.

Question6:Whatisthemaintopicofthelecture?

Question7:Accordingtotheprofessor,howdoestheViceroybutterflybenefitfromresemblingtheMonarch?

Question8:HowdoestheprofessorexplainMüllerianmimicry?

Question9:Whatisaggressivemimicry?

Question10:Whydoestheprofessormentionthebolasspider?

Conversation2

(Librarianspeakingwithastudent)

Student:Hi,I’mlookingforabookcalled"TheUrbanForest."Ithinkit’sbyaresearchernamed...maybeDr.Thorne?

Librarian:Letmecheckthecatalog.(Typing)Wehaveabook"TheUrbanForest:PlanningandManagingGreenInfrastructure."TheauthorisDr.AlanThorne.

Student:Yes,that’stheone!Ineeditforapaperonurbanheatislands.

Librarian:Okay,itlookslikeitiscurrentlycheckedout.ItisduebacknextTuesday.However,wehaveadigitalversionavailablethroughourdatabase.Youcanaccessitonlinefromanycampuscomputer.

Student:Oh,that’sconvenient.ButIalsoneedtofindsomearticleson"verticalgardens."Doyouhaveanyjournals?

Librarian:Certainly.Irecommendthe"JournalofSustainableArchitecture."Youcanusethesearchterminalsoverthere.Typein"verticalgardens"or"greenwalls."Also,makesuretochecktheboxfor"peer-reviewed"tolimityourresultstoacademicsources.

Student:Great.Onemorething—myprofessorsaidweneedtocitesourcesinAPAstyle.Doyouhaveaguideforthat?

Librarian:Wedo.Therearehandoutsonthereferencedeskneartheentrance,oryoucanaccessthePurdueOWLguideonline,whichisexcellent.

Student:Thanksalotforyourhelp.

Question11:Whatisthestudent'sinitialrequest?

Question12:Whycan'tthestudentgetthephysicalbookimmediately?

Question13:Howcanthestudentaccessthebook"TheUrbanForest"?

Question14:Whatadvicedoesthelibrariangiveregardingthesearchforarticles?

Question15:Whatdoesthestudentneedhelpwithattheendoftheconversation?

Lecture2:Physics-AcousticsandSound

Professor:We'vebeendiscussingwavemechanics.Today,let'sapplythattosound.Soundisalongitudinalwave,meaningtheparticledisplacementisparalleltothedirectionofwavepropagation.Weperceivesoundbasedontwoprimarycharacteristics:frequencyandamplitude.Frequencydeterminespitch,andamplitudedeterminesloudness.

However,therelationshipbetweenamplitudeandloudnessisn'tlinear.Ourearsaresensitivetoavastrangeofpressures.Tomanagethis,weusethedecibelscale,whichislogarithmic.Theintensitylevelβindecibelsisdefinedbytheformula:

β=10lo()

whereIistheintensityofthesound,andisthereferenceintensity,usuallytakenasthethresholdofhearing,wattspersquaremeter.

Thislogarithmicnaturemeansthataddingtwosoundsourcesofequalintensitydoesnotdoublethedecibellevel.Forinstance,two60dBspeakersdonotproduce120dB.Instead,doublingtheintensityaddsonlyabout3dB.So,two60dBsourcesproduceapproximately63dB.Thisisacommonpointofconfusion.

Furthermore,whensoundwavesinteract,theycaninterfereconstructivelyordestructively.Iftwowavesareinphase—peaksalignwithpeaks—thesoundgetslouder.Iftheyareoutofphase—peaksalignwithtroughs—theycancanceleachotherout.Thisprincipleisusedinnoise-cancelingheadphones.Theheadphoneshaveamicrophonethatpicksupambientnoise.Theelectronicsgenerateasoundwavethatistheexactinverse(180degreesoutofphase)ofthenoise,effectivelysilencingitforthelistener.

Question16:Whatdeterminesthepitchofasound?

Question17:Whyisthedecibelscalelogarithmic?

Question18:Accordingtothelecture,whathappensifyoucombinetwosoundsourcesof60dB?

Question19:Howdonoise-cancelingheadphoneswork?

Question20:Whatformulaispresentedinthelecture?

Lecture3:ArtHistory-Cubism

Professor:Intheearly20thcentury,aradicalmovementemergedinParis:Cubism.PioneeredbyPabloPicassoandGeorgesBraque,CubismrejectedthetraditionalperspectivethathaddominatedWesternartsincetheRenaissance.Insteadofviewingasubjectfromasingle,fixedangle,Cubistsdepictedobjectsfrommultipleviewpointssimultaneously,fragmentingandanalyzingthem.

ThefirstphaseisAnalyticalCubism,roughlyfrom1908to1912.Paintingsfromthisperiodarecharacterizedbymonochromaticpalettes—browns,grays,andblacks.Thefocuswasonformandstructureratherthancolor.Theartistsbrokedownobjectsintogeometricshapes—cubes,cones,andspheres.It’softendifficulttorecognizethesubjectmatterinthesepaintingsbecausetheformsaresointerwoven.Forexample,inPicasso's"MaJolie,"thefigureandtheviolinarealmostindistinguishablefromthebackground.

FollowingthiswasSyntheticCubism,whichlasteduntilaround1919.Here,theartistsmovedfrom"analyzing"formsto"synthesizing"orconstructingthem.Theyintroducedbrightercolorsandsimplershapes.Akeytechniquewastheuseofcollage.Theypastednewspaperclippings,wallpaper,andchaircaningdirectlyontothecanvas.Thiswasrevolutionarybecauseitchallengedtheideathatpaintinghadtobecreatedentirelyfrompaint.Itintroducedtherealworldintotheart,blurringthelinebetweenhighartandeverydaylife.Theinclusionoftext,like"LeJournal"inBraque'swork,alsoplayedwiththeviewer'sperceptionofrealityandrepresentation.

Question21:Whatisthemainsubjectofthelecture?

Question22:HowdidCubismdifferfromtraditionalRenaissanceart?

Question23:WhatcharacterizesAnalyticalCubism?

Question24:WhatisakeyfeatureofSyntheticCubism?

Question25:WhydidCubistsusecollage?

SpeakingSection

Task1

Somepeoplebelievethatuniversitiesshouldrequirestudentstotakepublicspeakingcourses,regardlessoftheirmajor.Othersbelievethatthesecoursesshouldonlybeoptional.Whichviewdoyouagreewithandwhy?

Task2

Theuniversityadministrationhasannoun