第16講閱讀理解主旨大意題（精講）-2024年高考英語(yǔ)高頻考點(diǎn)題型歸納與方法總結(jié)（新高考通用）原卷版

【一輪復(fù)習(xí)講義】2024年高考英語(yǔ)高頻考點(diǎn)題型歸納與方法總結(jié)（新高考通用）第16講閱讀理解主旨大意題（精講）題型目錄一覽段落大意標(biāo)題概括一、知識(shí)點(diǎn)梳理一、知識(shí)點(diǎn)梳理這類(lèi)題目考查的范圍是基本論點(diǎn)、文章標(biāo)題、主題或段落大意等。要求考生在理解全文的基礎(chǔ)上能較好地運(yùn)用概括、判斷、歸納、推理等邏輯思維方法，對(duì)文章進(jìn)行高度概括或總結(jié)，語(yǔ)言一般簡(jiǎn)潔、凝練，其干擾項(xiàng)的設(shè)置往往比較有迷惑性，屬于高層次的閱讀理解題。技巧點(diǎn)撥1.標(biāo)題是段落中心思想最精煉的表達(dá)形式。文章標(biāo)題可以是單詞、短語(yǔ)，也可以是句子。它的特點(diǎn)是：短小精悍，多為一短語(yǔ)；涵蓋性強(qiáng)，一般要求能涵蓋全文，其確定的范圍要恰當(dāng)，不能太大，也不能太?。痪_性強(qiáng)，不能隨意改變語(yǔ)言表意的程度及色彩。2.主旨大意題，要搞清楚是問(wèn)某一段還是全文的大意，可利用文中主要信息來(lái)把握文脈，進(jìn)行綜合歸納。如有標(biāo)題，標(biāo)題中蘊(yùn)含的信息往往是關(guān)鍵信息。另外，任何一篇文章都是圍繞某個(gè)主題展開(kāi)的，因此，許多文章中最明顯的特點(diǎn)之一是有一個(gè)反復(fù)出現(xiàn)的中心詞，即高頻詞，也叫主題詞。抓住了它，便容易抓住文章的中心。題型一段落大意【典例1】(2022·全國(guó)甲卷)Sometimeintheearly1960s,asignificantthinghappenedinSydney,Australia.Thecitydiscovereditsharbor.Then,oneafteranother,Sydneydiscoveredlotsofthingsthatwerejustsortofthere—broadparks,superbbeaches,andaculturallydiversepopulation.Butitistheharborthatmakesthecity.AndrewReynolds,acheerfulfellowinhisearly30s,pilotsSydneyferryboatsforaliving.Ispentthewholemorningshuttlingbackandforthacrosstheharbor.AfterourthirdrunAndrewshutdowntheengine,andwewentourseparateways—heforalunchbreak,Itoexplorethecity.“I'llmisstheseoldboats,”hesaidasweparted.“Howdoyoumean?”Iasked.“Oh,they'rereplacingthemwithcatamarans.Catamaransarefaster,butthey'renotsoelegant,andthey'renotfuntopilot.Butthat'sprogress,Iguess.”EverywhereinSydneythesedays,changeandprogressarethewatchwords(口號(hào)),andtraditionsareincreasinglyrare.ShirleyFitzgerald,thecity'sofficialhistorian,toldmethatinitsrushtomodernityinthe1970s,Sydneysweptasidemuchofitspast,includingmanyofitsfinestbuildings.“Sydneyisconfusedaboutitself,”shesaid.“Wecan'tseemtomakeupourmindswhetherwewantamoderncityoratraditionalone.It'saconflictthatwearen'tgettinganybetteratresolving(解決).”O(jiān)ntheotherhand,beingyoungandoldatthesametimehasitsattractions.IconsideredthiswhenImetathoughtfulyoungbusinessmannamedAnthony.“Manypeoplesaythatwelackcultureinthiscountry,”hetoldme.“WhatpeopleforgetisthattheItalians,whentheycametoAustralia,brought2000yearsoftheirculture,theGreekssome3000years,andtheChinesemorestill.We'vegotafoundationbuiltonancientculturesbutwithadriveanddynamismofayoungcountry.It'saprettyhardcombinationtobeat.”Heisright,butIcan'thelpwishingtheywouldkeepthoseoldferries.32.Whatisthefirstparagraphmainlyabout?A.Sydney'sstrikingarchitecture.B.TheculturaldiversityofSydney.C.ThekeytoSydney'sdevelopment.D.Sydney'stouristattractionsinthe1960s.【典例2】(2022·新高考Ⅰ卷)Humanspeechcontainsmorethan2,000differentsounds,fromthecommon“m”and“a”totherareclicksofsomesouthernAfricanlanguages.Butwhyarecertainsoundsmorecommonthanothers?Aground-breaking,five-yearstudyshowsthatdiet-relatedchangesinhumanbiteledtonewspeechsoundsthatarenowfoundinhalftheworld'slanguages.Morethan30yearsago,thescholarCharlesHockettnotedthatspeechsoundscalledlabiodentals,suchas“f”and“v”,weremorecommoninthelanguagesofsocietiesthatatesofterfoods.NowateamofresearchersledbyDamiánBlasiattheUniversityofZurich,Switzerland,hasfoundhowandwhythistrendarose.Theydiscoveredthattheupperandlowerfrontteethofancienthumanadultswerealigned(對(duì)齊),makingithardtoproducelabiodentals,whichareformedbytouchingthelowerliptotheupperteeth.Later,ourjawschangedtoanoverbitestructure(結(jié)構(gòu)),makingiteasiertoproducesuchsounds.TheteamshowedthatthischangeinbitewasconnectedwiththedevelopmentofagricultureintheNeolithicperiod.Foodbecameeasiertochewatthispoint.Thejawbonedidn'thavetodoasmuchworkandsodidn'tgrowtobesolarge.AnalysesofalanguagedatabasealsoconfirmedthattherewasaglobalchangeinthesoundofworldlanguagesaftertheNeolithicage,withtheuseof“f”and“v”increasingremarkablyduringthelastfewthousandyears.Thesesoundsarestillnotfoundinthelanguagesofmanyhunter-gathererpeopletoday.Thisresearchoverturnsthepopularviewthatallhumanspeechsoundswerepresentwhenhumanbeingsevolvedaround300,000yearsago.“Thesetofspeechsoundsweusehasnotnecessarilyremainedstablesincetheappearanceofhumanbeings,butratherthehugevarietyofspeechsoundsthatwefindtodayistheproductofacomplexinterplayofthingslikebiologicalchangeandculturalevolution,”saidStevenMoran,amemberoftheresearchteam.34.WhatisParagraph5mainlyabout?A.Supportingevidencefortheresearchresults.B.Potentialapplicationoftheresearchfindings.C.Afurtherexplanationoftheresearchmethods.D.Areasonabledoubtabouttheresearchprocess.題型二標(biāo)題概括【典例1】(2022·全國(guó)甲卷)AsGinniBazlintonreachedAntarctica,shefoundherselfgreetedbyagroupoflittleGentoopenguins(企鵝)longingtosayhello.Thesegentle,lovelygatekeeperswelcomedherandkick-startedwhatwastobeatripGinniwouldneverforget.Eversinceherchildhood,Ginni,now71,hashadadeeplovefortravel.Throughouthercareer(職業(yè))asaprofessionaldancer,shetouredintheUK,butalwayslongedtoexplorefurther.Whensheretiredfromdancingandhersonseventuallyflewthenest,shedecideditwastimetotaketheplunge.

AftertakingadegreeatChichesterUniversityinRelatedArts,Ginnibegantotraveltheworld,eventuallygettingworkteachingEnglishinJapanandChile.AnditwasinChileshediscoveredshecouldgetlast-minutecheapdealsonshipsgoingtoAntarcticafromtheislandsoffTierradelFuego,thesouthernmosttipoftheSouthAmericanmainland.“IjustdecidedIwantedtogo,”shesays.“IhadnoideaaboutwhatI'dfindthereandIwasn'tnervous,Ijustwantedtodoit.AndIwantedtodoitaloneasIalwayspreferitthatway.”InMarch2008,Ginniboardedashipwith48passengersshe'dnevermetbefore,tobeginthejourneytowardsAntarctica.“Fromseeingthewildlifetowitnessingsunrises,thewholeexperiencewasamazing.Antarcticaleftanimpressiononmethatnootherplacehas,”Ginnisays.“IrememberthefirsttimeIsawahumpbackwhale;itjustroseoutofthewaterlikesomeprehistoriccreatureandIthoughtitwassmilingatus.Youcouldstillheartheoperaticsoundsitwasmakingunderwater.”Therealizationthatthisisapreciousland,toberespectedbyhumans,wasoneofthebiggestthingsthathithometoGinni.31.Whatisthetextmainlyabout?A.Achildhooddream.B.Anunforgettableexperience.C.Sailingaroundtheworld.D.MeetinganimalsinAntarctica.【典例2】(2022·全國(guó)甲卷)Goffin'scockatoos,akindofsmallparrotnativetoAustralasia,havebeenshowntohavesimilarshape-recognitionabilitiestoahumantwo-year-old.Thoughnotknowntousetoolsinthewild,thebirdshaveprovedskilfulattoolusewhilekeptinthecage.Inarecentexperiment,cockatooswerepresentedwithaboxwithanutinsideit.Theclearfrontoftheboxhada“keyhole”inageometricshape,andthebirdsweregivenfivedifferentlyshaped“keys”tochoosefrom.Insertingthecorrect“key”wouldletoutthenut.Inhumans,babiescanputaroundshapeinaroundholefromaroundoneyearofage,butitwillbeanotheryearbeforetheyareabletodothesamewithlesssymmetrical(對(duì)稱(chēng)的)shapes.Thisabilitytorecognizethatashapewillneedtobeturnedinaspecificdirectionbeforeitwillfitiscalledan“allocentricframeofreference”.Intheexperiment,Goffin'scockatooswereabletoselecttherighttoolforthejob,inmostcases,byvisualrecognitionalone.Wheretrial-and-errorwasused,thecockatoosdidbetterthanmonkeysinsimilartests.ThisindicatesthatGoffin'scockatoosdoindeedpossessanallocentricframeofreferencewhenmovingobjectsinspace,similartotwo-year-oldbabies.Thenextstep,accordingtotheresearchers,istotryandworkoutwhetherthecockatoosrelyentirelyonvisualclues(線(xiàn)索),oralsouseasenseoftouchinmakingtheirshapeselections.27.Whichcanbeasuitabletitleforthetext?A.Cockatoos:QuickErrorCheckersB.Cockatoos:IndependentLearnersC.Cockatoos:CleverSignal-ReadersD.Cockatoos:SkilfulShape-Sorters【題型訓(xùn)練】1.AnewstudyshowsthatincreasesinextremewinterweatherinpartsoftheUSarelinkedtoquickenedwarmingoftheArctic.Overthepastfourdecades,warmingintheArctichasbeenfarmoredefinitethanthatintherestoftheworldandhascausedarapiddecreaseofsummerseaice.HeatingintheArctichasultimatelydisturbedthecircularpatternofwindsknownasthepolarvortex(旋渦).Asaresult,itgotstretchedoutofshapeandslidsouthwardoffthepole.ScientistsbelievethisvortexstretchingprocessledtothedeadlyTexascoldwaveinFebruarythisyear.1.Whatisparagraph2mainlyabout?A.Theexplanationgivenbyscientists. B.TheformationofTexascoldwave.C.Thedecreaseofsummerseaice. D.Thepolarvortex’sbeingdisturbed.2.AlexDunedinthrewhissmartphoneintherubbishbag2yearsago.“Culturally,wehavebecomeaddictedtothesetools,”saysthiseducationalresearcherandtechnologyexpert.“Theyareweakeningcognition(認(rèn)知)andimpeding(妨礙，阻礙)productivity.”Dunedinsaysanotherreasonbehindhisdecisionwasenvironmentalconcerns.“WearewastinglargeamountsofenergyandproducinglargeamountsofCO2emissions.”2.Whatisparagraph4mainlyabout?A.ThebenefitsAlexDunedin’ssmartphonebrought.B.ThecharacteristicsofAlexDunedin’ssmartphone.C.ThereasonswhyAlexDunedinabandonedhissmartphone.D.ThewaysAlexDunedinreducedtimespentonasmartphone.3.Thereviewpointstodisappearinganddegradedhabitat—resultingfromclimatechange,urbanization,agriculturalintensification,andinternationaltrade—astheleadingdriverofbirddeclinesworldwide.Inanoteofhope,theauthorscitea2020studyindicatingthatrestoringjust5%ofhabitatinpriorityareasaroundtheworldcouldavert60%oflikelyextinctions.LeadauthorAlexanderLees,aresearchassociateattheCormellLab,alsopointstotheneedforsubstantialchangesinhumanbehaviortopreventfurtherlosses.“Lossanddegradationofhabitatisoftendrivenbydemandforresources,”saysLees.“Weneedtobetterconsiderhowcommodityflowssuchasbeef,oil,andseedcropscancontributetobiodiversitylossandtrytoreducethehumanfootprintonthenaturalworld.”3.Whatisthelastparagraphmainlyabout?A.Extrareasonsforbirdextinction. B.Possiblesolutionstohabitatloss.C.Substantialchangesinhumanbehavior. D.Theprospectofbiodiversityloss.4.IstartedplayingthepianowhenIwasaroundfouryearsold—thatwas15yearsago!—andsincethen,thelongestIhaven’ttouchedpianokeyswasprobablytwomonths.ThiswasanenormousamountofdevotiontosomethingthatIwasn’tevenplanningtomakemoneyoffofit—sotheremusthavebeensomethingworthholdingonto,right?TheeasyguessisthatIwasalwayssopurelyinlovewithmusicandpianothatIcouldn’tbeartoletthemgo.However,it’sabitmorecomplicatedthanthat.Istruggledalotwithpiano.Ifeltpressuretoimprove,innovate,andbethebestinordertoprovesomethingtoothers.Theseedofmymusicalinterestwasgrownwithcompetitionanddoubt.It’sdifficulttolearntolovesomethingthatyoudidn’tchooseinthefirstplace.Butsomehow,sometime,lovegrew.Andbyhighschool,itwasstrongenoughthatIfoundthestrengthtoholdontighter,digfurther,andfindsomethingofmyowntogrow.Inaway,Ihadtostartover.Andso,Itookapause.Iswitchedteachers,andgotincrediblyluckywithonewhoencouragedmeandhelpedmetunnelintowhatIloved,notwhatIwastoldIshouldlearn.AnythingIhadwasgoodenoughtobeloved.Thissummer,Istartedlearningtheguitar.Ideliberatelywantedtolearnonmyown—thiswasjustforme,toformanewrelationshiptomusic.Eventhoughmyguitarskillsaremileslowerthanmypianoskills,IfeelIcanexpressmyselfevenmorewhollythroughstringsthankeys.There’sjustsomethingaboutdoingitallformyselfthathashelpedmehealthedamagestomyrelationshiptomusic.TheloveandhateI’vehadforthepianowerebothplantedandgrown.Ifyoutoohavelearnedtohatesomethingyouonceloved—orsomethingyouneverchose—rememberthatwithdedication,itcanbeuprooted,andlovecanmakeahomeinitsplace.Thereisalwaystime.Thereisalwaysroom.4.Whatisthebesttitleforthetext?A.Practicemakesperfect B.LovecannotbeforcedC.Loveisathingthatgrows D.Thereisnoendtolearning5.“Regrets,I’vehadafew.Butthenagain,toofewtomention,”FrankSinatrachantedinhis1969hit“MyWay”.Thesong’sideaisattractive:thatanyonecanjustdeclarewhat’sdoneisdoneandmoveon.Sometakethedeclarationastepfurtherandclaimtheyhavenoregretsatall.Whetheraboastoranactualattitude,“noregrets”suggeststhatlifecanandshouldbelivedwithoutlookingthroughtherear-viewmirror.Easiersaidthandone,though.In2020,authorDanielH.PinklaunchedtheWorldRegretSurvey,thelargesteversurveyonthetopic.Withhisresearchteam,Pinkaskedmorethan15,000peoplein105countries,“Howoftendoyoulookbackonyourlifeandwishyouhaddonethingsdifferently?”82%saidregretisatleastanoccasionalpartoftheirlife;roughly21%saidtheyfeelregret“al1thetime.”O(jiān)nly1%saidtheyneverfeelregret.Ifyouareofthe“noregrets”type,youmightthinkthatallthisregretisarecipeforunhappiness.Butthatisn’tthecase.True,beingoverwhelmedbyregretisindeedbadforyou.Butgoingtotheotherextrememaybeevenworse.Toridyourselfofregretsdoesn’tfreeyoufromshameorsorrow;itleadsyoutomakethesamemistakesagainandagain.Totrulygetoverourguiltrequiresthatweputregretinitsproperplace.Asuncomfortableasitis,regretisanamazingcognitive(認(rèn)知)achievement.Iftodayyourrelationshipwithyourpartnerhassoured,yourregretmightmentallytakeyoubacktolastyear.Youwouldrememberyourbeingmeanandsensitive,andthenimagineyourselfshowingmorepatience,beingkindinsteadofhurtfulatkeymoments.Thenyouwouldfast-forwardtotodayandseehowyourrelationshipcouldbeprogressinginsteadoflanguishing.Butregretdoesn’thavetobeleftunmanaged.Thetrickistoacknowledgeitanduseitforlearningandimprovement.Youcanbehonestwithyourselfaboutwhatwentwrongandusethatknowledgetoenjoybetterrelationshipsinthefuture.5.Whatmightbeasuitabletitleforthetext?A.Regrettobecomesmarter—ifyouletit. B.Longforadifferentpast?Regretit!C.Regret?Notmyway! D.Stayaway!Regretwillhealitself.6.EverysummerartistsperformatFringe(邊緣)Festivalsaroundtheworld.FringeFestivalsareacelebrationofstrangeart.Theyhaveallkindsofperformers—fromdancers,musiciansandactorstoeverythinginbetween.Theshowsgiveartistsachancetocreateunusualart.Forfestivalgoers,eachshowisatimetoexperiencesomethingdifferent.ThefirstFringeFestivalwasheldinEdinburgh,Scotlandin1947.ThatwasalsotheyearofthefirstEdinburghInternationalFestival.ArtistsfromaroundtheworldtraveledtoScotlandfortheEdinburghInternationalFestival.Theyperformedatartscentersthroughoutthecity.Eightlocaltheatercompaniesdidnotreceiveaninvitation,however.Inresponse,theyperformedatsmallerspacesaroundEdinburgh.Theseartistsperformedwherevertheycould,includingchurchesandevenonthestreet.TheystartedtheirownculturaleventandnamedittheEdinburghFestivalFringe.6.WhatdoesParagraph2mainlytalkabout?A.WhyEdinburghbecametheglobalartcenter. B.HowthefirstFringeFestivalcameintobeing.C.WhentheEdinburghInternationalFestivalwasheld. D.WheretheEdinburghFestivalFringewascelebrated.7.Theremaybeareasonwhyastronautsarecrazyabouttheviewfromspacebutnevermentionthefood.AstronautsaboardtheInternationalSpaceStationmustdrinkmealsoutofaplasticsqueeze-bagbecauseofzerogravity.Foodinspacecanonlybereheatedinsteadofbeingcookedfresh.Besides,mealsforeachcrewmembermustbestoredinadvanceandeateninorder.Allofthismaysoundalittledifficulttoaccept.Therefore,itwasonesmallstepforinterstellar(星際的)cuisinewhenU.S.astronautMeganMcArthurrecentlypostedphotosofherselfholdingapancakesgorgedwithbeef,tomatoesandafreshhatchchilli(紅番椒)grownaboardtheInternationalSpaceStationitself.“Bestspacepancakesyet,”shesharedonline.Pesquet,aFrenchastronaut,postedonInstagram,“Itissuchajoytogrow(andeat)yourownfood,andnecessaryforfurtherexplorationofourSolarSystem.”Itseemsthereisasuitcase-sizedspacegardenaboardtheISS(InternationalSpaceStation)thatholdsaboutsix“pillows”stuffedwithclayandfertilizer,andaLEDlight.AstronautshavegrownseveralkindsofvegetablesincludingChinesecabbageandredRussiankale(羽衣甘藍(lán))inthismicro-plot,totestwhichplantsmightgrowbestduringalongspacevoyage.WecalledMelvaAguirre,whoownsthePepperPotinHatch,N.M.,homeofhatchchilli.Shesaystheharvestoftheirfamouslocalcropinouterspaceisthetalkofthetown.“Nowthewholeuniverseknowshowgreatourchilliare,”shesaid.WhenIaskedifshecouldrecommendahatchchillirecipe,Aguirretoldme,“Juststuffit.”“Stuffit?”Iasked,andshelaughedandsaid,“Imean,inyourmouth.”ArecipeevenIcanfollow.7.Whatisthebesttitleforthepassage?A.ChallengesAstronautsFaceinSpace.B.TheBestFoodEverforSpaceVoyages.C.FineDiningontheInternationalSpaceStation.D.TheConstantStepsofHuman’sSpaceExploration.8.Withclimatechangeontracktodestroytheworld’scoralreefs,scientistsracetocreateanewsuper-coralthatcansurviveextremetemperatures.AtypeofmicroscopicalgaecalledSymbiodiniaceaeliveswithinmostcoral’stissues.Thetwoorganismshavebeenlivingdependentlyforhundredsofmillionsofyearsinawaythatresemblestherelationshipbetweenhumansandtrees.Thealgaeconsumecoral’swasteproducts,andcoralconsumesnutrientsthatthealgaephotosynthesize.Coralalsoprovidesshelterforalgae.Butwhenexposedtotoomuchheatorlight,thealgaereleaseharmfulchemicals,sothecoralcaststhemout.Leftwithouttheirmainenergysource,thecoralwillstarvetodeath.Thisisalsobadnewsforthealgae.Butnaturalevolutionhasprovidedabiologicalfeedbackloopthatcanhelpthetworeunite.Oneofthecompoundsthatalgaereleasewhenwaterbecomeshot,calledDMs,bubblesuptothesurfaceofthewaterandformsathinlayer,whichshieldsthecorallikeanatural,on-demandlayerofsunscreen.Withthisprotection,thewatercoolsdownandalgaecanreturntothecoralandreestablishtheirpartnershipunlessthewateristoohot,inwhichcasethecoralconsumesthecomponentsthatmakeupDMsbeforeitcanform.Climatechangeisbecomingtoointenseforcoralandalgaetonaturallyadaptfastenough.Therefore,scientistsaretestingoutdifferentwaystoacceleratethatadaptationthroughvariousmethodsofassistedevolution.Someteamsarecurrentlyconductingsmallfieldtrialsofselectivebreeding,wheretheyidentifythemostheat-tolerantmembersofasampleofcorals.Thentheybreedthemtogethertocreateoffspringthatcanbeusedtohelprestorecoralreefs.Othersarefocusingtheireffortsonspeedingupthealgae’sadaptation,attemptingtoincreaseitsheattoleranceinlabs.Ultimately,scientistsmayimplementacocktailofsolutionstosavecoralreefs.“Tocreateasuper-coral,wecould,forexample,selectivelybreedheat-tolerantcoralsandcombinethatwithenhancedalgae,”saysvanOppen.8.Whatisthepassagemainlyabout?A.Theroleplayedbythealgaewithinthecoral.B.Thewaytocreateasuper-coraltosavereefs.C.Selectivebreedingconductedamongcorals.D.Scientists’effortstoincreasealgae’sheattolerance.9.CouldasuddensharpincreaseinthesizeandvarietyofancientlifehavebeenlinkedtodramaticchangesdeepinsidetheEarth?About550millionyearsago,intheCambrian(寒武紀(jì))periodofprehistorysomanynewanimalsappearedthattheeventisreferredtoasthe“Cambrianexplosion”.Scientistshavelongwonderedwhattriggeredthechange,afterbillionsofyearsinwhichlifewasmostlyextremelysmall.NowitseemsthattheformationofEarth’sinnercore—asolidironballatthecentreofEarth—wascrucial.Theinnercoreliesabout3,000milesbelowEarth’ssurfaceandis1,500milesacross.Itissurroundedbyaliquid-metaloutercoreandisslowlygrowingastheliquidmetalcools.Heatfromtheinnercorepowersswirling(旋轉(zhuǎn))movementsintheliquidlayer,whichcreateastrongmagneticfield(磁場(chǎng))aroundEarth—abarrierthatprotectslifebyblockingharmfulparticlesfromouterspace.Themagnetism-drivinginnercoreseemstobearecentarrival,however.In2019ateamledbyProfessorJohnTardunoattheUniversityofRochester,NewYork,Us,analysedchemicalsinancientrocksfromQuebecCanada,whichtraparecordofthemagneticfieldatthemomenttheyformed.Theteamfoundthat565millionyearsago,Earth’smagnetismhadlessthan10%ofitsstrengthtoday.Thissuggeststhattheswirlingofliquidmetal,whichhadalwaysproducedaprotectivemagneticforce,wasgrowingweak.Now,furtherworkhasshownthatthefield’sstrengthstartedtorecoverjustbeforetheCambrianexplosion—almostcertainlydrivenbythenewlyformedinnercoreprovidingafreshpowersource.Itseemshighlylikelythatthetwoeventsaresomehowlinked.“Idon’tthinkthattheret