高考英语二轮复习阅读理解分类训练：人与自然类 (含答案)

阅读理解ECyclingreferstotherecyclingofelectronicitems,whicharebecomingacommonprobleminAmericanhomeandthroughouttheworld.TheEPA,orEnvironmentalProtectionAgency,hasactuallystartedaprogramtohelpandmotivatetherecyclingofelectronics.Togettheprogramtotheregionalandneighborhoodlevels,theEPAdirected“Plug-IntoeCyclingPartners.”Thesepartnershipssupportelectronicreusingprogramsinindividualcommunities.Theyprovidelocalgovernments,retailersandmanufacturerswithopportunitiestoreuseandrecycletheiritems.Thosewhomakeandofferelectronicdevicesthenpromoteprogramsandopportunitiesforconsumerstoreusetheirsecond-handelectronicproducts.OneoftheEPA’sgoalsistoenlightencustomersaboutwhytherecyclingofelectronicsissoimportant.TheylikewisewishtomakeeCyclingchanceseasilyaccessibletospecificconsumersandtheirfamilyelectronics.AccordingtotheEPA,theeCyclingprogramhasactuallybeenquitesuccessful.In2008,theEPAcollected66.5millionpoundsofelectronicdevicesthroughtheirPlug-InPartners.Localgovernmentshaveactuallylikewisegotonboardandpassedlawsintendedtohandleusedelectronicdevices.HugecorporationshaveactuallyintroducedeCyclingprogramsattheirlocalretailstores.Onesellerofferscustomerssmall,mediumandbigboxesforsale,whichthecustomersthenloadwithusedelectronicsandgobacktothestore.Typically,customersbringtheirrecyclableelectronicstoalocation.WhentheelectronicitemsaregatheredbytheEPA(typicallythisisdonebythePartners),theyarereusedorrecycled.Reuseditemsarerepairedandrefurbished,andpassedontoothersasacontribution.Youcanrepairorreconditionyourveryownelectronicdevicestoo,extendingthelifeoftheitemsandconservingtheenergyofmakingnewmaterials.Reusingelectronicdevicesincludesmakinguseoftheproductsandpartsoftheitems.Thesematerialsandpartsarethenmadeuseoftoproduceanotheritem.Thisismoreefficientthanmakingitemsfromnewmaterials.SomeitemsthatarecommonlyeCycledconsistoftelevisions,computermonitors,printers,notebookcomputer,keyboardsandcabletelevisions.Lessusualitemsincludecopyingmachines,CDplayers,voicemailmachines,computerharddrives,mobiletelephones,remotecontrols,radios,batteries,telephones,facsimilemachinesandcomputergames.Occasionally,electronicitemssuchasmicrowaves,fans,vacuums,smokealarms,andtoastersareeCycled.AstheeCyclingprogramcontinues,youoryourorganizationmaywanttogetinvolved.ChecktheEPA’sinternetsite()forregionaleCyclingprograms,orfordetailsonhowyourcompanycanparticipate.TheirwebsitehaslinkstoorganizationsthataretakingpartintheeCyclingprogram.1．TheEPAbroughtabout“Plug-IntoeCyclingPartners”to________.A．makeandofferelectronicdevicestoconsumersB．makecustomersunderstandtheimportanceofeCyclingC．makeitpossibleforconsumerstoreusetheirusede-productsD．maketheprogramaccessibletolocalregionsandcommunities2．ThePlug-InPartnersaremainlyengagedin________.A．offeringcustomersdifferentboxesforsaleB．reusingsecond-hande-productsC．gatheringrecyclableelectronicsD．repairingelectronicdevice3．Whatisthemainpurposeofthispassage?A．TocallonlocalgovernmentstosupportPlug-InPartners.B．ToattractpeopletojoinintheeCyclingprograms.C．Toteachcustomershowtorecycleelectronics.D．Tointroduceanewwaytosavecosts.WhenIgivepubliclecturesabouttheclimatecrisis,themostcommonquestionpeopleposeis:“Areyouanoptimistorapessimist?”Myanswerisyes.Californiahasachieveddramaticemissionsreductionsinathrivingeconomy,whichmakesmehopeful,yetingeneralthefossil-fuelindustryisdeterminednottochange.Thesecondmostcommonquestionis:“WhatcanI,personally,do?”That’satoughone.Themajordriversofclimatechangearecollectiveenterprisessuchaspowergrids,industry,large-scaleagricultureandtransportationsystems.Substantialemissionsreductionsinthesesettingsmostlikelywillnotcomefrompersonalactions;theywillcomefromlawsandpoliciessuchascarbon-pricingsystems,revisedbuildingcodesandsupportsforgreeninvestment.Somepeoplehavearguedthatcallsforindividualactionactuallydistractusfromcorporateresponsibility.Thatcouldexplainwhythefossil-fuelindustryisfondofsuchrequests.OilgiantBPpopularizedandpromotedtheideaofacarbonfootprint,deflectingattentiontoitscustomerswho,itsuggests,shouldtakepersonalresponsibilitybyloweringtheircarbonfootprints.Onestudyfoundthatfocusingonindividualactivityactuallyunderminessupportformoreeffectivepolicyinitiativessuchasacarbontax.Anotherproblemwithpersonalbehavioristhatpeopledonotliketobetoldwhattodo.Yetindividualactscangrowintoinfluentialgroupactivity.Oneeffectiveact,andonethatcanbeamplified,istoeatlessredmeat.CuttingmeatconsumptionisapowerfulandpersonalthingmostAmericanscandototackletheclimatecrisis,andtheycandoitimmediately.About40percentofgreenhousegasescomefromagriculture,deforestationandotherland-usechanges.Meat—particularlybeef—drivesclimatechangeintwoways:first,throughcows’emissionofmethane,apotentgreenhousegas,andsecond,bydestroyingforestsastheyareconvertedtograzinglandtosatisfytheglobaldemandforbeef.Byeatinglessbeef,wecanstarttodecreasethatdemand.Youdonothavetobecomeavegantodothis.IfeverypersonintheU.S.cuttheirmeatconsumptionby25percent,itwouldreduceannualgreenhousegasemissionsby1percent.Thatmightnotsoundlikealot,butitwouldhelpprotecttherainforest,sothepositiveeffects—includingreducedwaterandfertilizeruse,improvedbiodiversityandsafeguardedrightsofindigenouspeoples—wouldbeamplified.Perhapsmostimportant,socialactioniscontagious—inagoodway.Iflotsofusbegintoeatlessmeatandifwetalkaboutitconstructively,wewilllikelyinfluenceothers.Prettysoonthe1percentreductionbecomes2percentormore.Reduceddemandformeatcouldmotivatemylocalsupermarkettocarrybetterproduce,makingiteasierformeandmyneighborstoprepareafewmoresatisfyingmeat-freemeals.Ultimatelychangesindemandwillinfluenceindustry.Fortyyearsagofewmainstreamsupermarketscarriedorganicproducts;nownearlyalldo.Consumerdemanddidthat.Cuttingbackonredmeatalsohastheaddedbenefitofbeinggoodforyourhealth.SowhileIwouldn’tadvisegovernmentstoorderpeopletostopeatinghamburgers,ifanyoneasks,“WhatcanIdo?”asimpleandaccurateansweris:“Eatlessmeat.It’sinyourcontrol,andyoucanbeginrightnow.Itbenefitsbothyouandtheplanet.”4．Whichoneplaysthemostdecisiveroleinemissionsreductionsaccordingtothepassage?A．Individualactions. B．Fossil-fuelindustries.C．Thethrivingeconomy. D．Effectivelawsandpolicies.5．Whatdowelearnfromthepassage?A．Indigenouspeoplesturnforestsintograzingland.B．Meatisconsideredasthebiggestdriverofclimatechange.C．Smallindividualactscanmakeabigdifferencecollectively.D．MostAmericanshavetobecomeveganstotackletheclimatecrisis.6．Whatdoestheunderlinedword“contagious”inParagraph6mean?A．Appealing. B．Poisonous. C．Harmonious. D．Spreading.7．Whatisthepurposeoftheauthorwritingthispassage？A．Toexplainwaystoreducecarbonfootprint.B．Topersuadepeopletocutmeatconsumption.C．Toevaluatetheeffectsofhealthyeatinghabits.D．Toargueagainsttheemissionpoliciesofindustries.Itwas2005andscientistsinCapeTownmadeashockingdiscovery.TheirtrackingdatashowedagreatwhitesharkmovingfromSouthAfricatoAustraliaandbackagaininanearstraightline.Itwasthefastesttransoceanicreturnmigrationeverrecordedanditwascarriedoutwithnearpinpointaccuracy.Today,it’swellknownthatsharksmakeyearlyreturnssuchasthistospecificlocations,buthowexactlytheydoithasescapedconsensus.AgroupofscientistsfromFloridaStateUniversityhastakenonthequestionandconcludedthatsharkshaveaninternal,GPS-likenavigationsystemthatallowsthemtoreadtheEarth’sgeomagneticfield.Toconducttheresearch,theteamfirstgot20juvenilebonnetheadsharksinStGeorgeSoundofftheFloridaPanhandle,andplacedtheminasmallpoolsurroundedbycopperwire.Thewireallowedtheresearcherstocreateacustommagneticfieldinthecentreofthepool.Exposedtothemagneticfieldfromthecapturelocation,thesharksswaminrandomdirectionsatleisure;butwhenexposedtothegeomagneticfieldthatwouldbefound600kilometressouthofthatspot,theyswamnorthina“homewardorientation”.Researchershavesuspectedthatsharksandsawfishdetectmagneticfieldssincethe1970s,buttheexactmechanismbywhichtheydoso,andtheprevalenceofthisskillinnaturehasprovenelusive,partlybecauseit’ssodifficulttostudy.“We’veknownforsometimethatsharkshavetheabilitytodetectthemagneticfield,butthisisthefirsttimeithasbeentestedsuccessfully,”saysBryanKeller,ascientistattheUSNationalOceanicandAtmosphericAdministration.“Weexpecttheseabilitiesarealsoobservedinotherspecies,likethegreatwhite,whichmigrate20,000kilometresoutandbacktothesamespot.”Theresultsmeanthatsomesharkscanbeaddedtothegrowinglistofanimalsthatnavigatebymagneticsensation,whichincludesseaturtles,lobstersandbirds.Withthesharknavigationsystemnowdemonstrated,scientistswanttounderstandthemechanismbehindit.Twotheorieshaveemerged:someresearchersbelievethatitdependsonanironmineralcalledmagnetite;othersbelieveit’sbasedonamagnetic-field-sensingmoleculeintheretina(视网膜)oftheeyecalledcryptochrome.Boththeories,oracombinationofthetwo,areplausible.Magnetitehasbeenisolatedfrommanyanimaltissues,whileevidencefromstudiesinbirdssuggeststhattheysensetheinclinationofthemagneticfieldusingcryptochromemoleculesintheirretinas;thedirectionofthefieldistransmittedbytheopticnervetothebrain,whichallowsthemto“visualize”northandsouth.Butscientistsdon’tyetknowthepreciselocationofthecryptochromereceptors,orthebraincentresthatprocesstheinformationonthemagneticfield.There’smoreworktodototrulyunderstandthesemasterfulnavigators.8．ScientistsinCapeTowndiscoveredsharkscould______.A．migratefastandaccurately B．navigatebymagneticsystemC．detectmagneticfieldsprecisely D．swiminastraightlineperfectly9．IntheFloridaStateUniversityresearch,thesharksswamnorthbecausethey______.A．lostthenavigationsystem B．couldnotdetectmagneticfieldsC．sensedtheirhomemagneticfield D．wereexposedtoastrangemagneticfield10．Theunderlinedword“elusive”inparagraph3probablymeans______.A．unique B．unattainableC．complex D．superior11．Thelastparagraphmainlytalksabout______ofsharknavigationsystem.A．theevolution B．theapplicationC．theadvantages D．themechanismAgroupofblue-facedbirdsstepthroughthegrassshouldertoshoulder,redeyeslookingaround.Theylooklikemiddleschoolersseekingacafeteriatableatlunchtime.Perhapsthey’renotsodifferent.Anewstudy,ledbyDamienFarine,anornithologistwhostudiescollectivebehaviour,showsthatthevulturineguineafowlofeasternAfrica,likehumans,havemultilevelsocieties.Inthepast,scientistsassumedsuchsocialstructuresrequiredalotofbrainpower.Butthepea-brainedguineafowlarerevealingthefaultsinthatassumption.Theselargebirdswanderacrossthelandscapeinpacks,oftenwalkingsocloselythattheirbodiestouch.Theymayfighteachothertomaintaintheirstricthierarchies(等级制度),butatothertimestheyengageinfriendlybehaviourslikesharingfood.Suspectingtheguineafowlmighthaveasocialstructure,Dr.Farineandhiscolleaguesbeganathoroughstudyoftheirsociety.Forawholeyear,theymadedailyobservationsof441birds.Colouredlegbandsinuniquecombinationsletresearcherstelltheblack-and-bluebirdsapart.TheyalsoattachedGPSdevicestothebacksof58birds,whichletthemseeexactlywhereeverygroupwent,24hoursaday.Thefindingsoftheresearchsuggestthatthevulturineguineafowlhaveamultilevelsociety.Therearegroupswithingroupswithinthepopulationasawhole.Thereevenseemtobegroupsoffriendswithinthesmallgroups.Thisisthefirsttimeanyonehasobservedsuchasocietyinabird.AndDr.Farineemphasizesthisparticularbird’stinybrainsize:“Theydon’tonlyhavesmallbrainsrelativetomammals(哺乳动物),theyalsohavequitesmallbrainsrelativetootherbirds,”hesaid.Accordingtohim,livinginthiskindofsocietymightactuallymakeiteasiertokeeptrackofthesocialorder.Forexample,ifgroupsarestableandabirdcanidentifyjustoneortwoindividualswithinagroup,itknowswhichgroupit’slookingat—noneedforabrainthatcanrecognizeeverysingleanimal.Multilevelsocietiesalsoletanimalsadjusttheirgroupsizesbasedonwhateverchallengesthey’refacing.Dependingonwhatenemiesorresourcesarearound,itmightmakesensetotravelinacombinedgroupratherthanasmallerone.“Havingamultilevelstructuremaynotrequirehavingalargebrain,”Dr.Farinesaid.Theremaybemorebirdsandotheranimalsouttherethat,althoughsmall-brained,havesocietiesasmany-leveledasourown.12．Accordingtothepassage,whatinspiredDr.Farinetocarryoutthestudy?A．Theguineafowl’ssocialbehaviour. B．Previousassumptionsaboutbirds.C．Hisinterestinanimalbrainpower. D．Thefaultsinearlierresearch.13．WhatisParagraph4mainlyabout?A．Theresearchsubjects. B．Theresearchmethods.C．Theresearchfindings. D．Theresearchequipment.14．Whatcanbelearnedfromthepassage?A．Complexsocialsystemscanbeadisadvantagetotheguineafowl.B．Theguineafowlaregoodatrecognizingindividualsinagroup.C．Birdsmaintainsocialorderbytravellingincombinedgroups.D．Small-brainedanimalscanformmultilevelsocieties.Millionsofmigratory(迁徙的)birdsoccupyseasonallyfavorablebreeding(繁殖)groundsintheArctic,butscientistsknowlittleabouttheformation,maintenanceandfutureofthemigrationroutesofArcticbirdsandthegeneticdeterminantsofmigratorydistance.Inanewstudy,amultinationalteamofresearchersundertheleadershipofDr.ZHANXiangjiangfromtheInstituteofZoologyoftheChineseAcademyofSciencesintegratedtwostate-of-the-arttechniques-satellitetrackingandwholegenomesequencing(基因排序)-andestablishedacontinental-scalemigrationsystemofperegrinefalconsinEurasianArctic.Theresearcherstracked56peregrinefalconsfromsixEurasianArcticbreedingpopulationsandsequenced35genomesfromfourofthesepopulationstostudythemigrationofthisspecies.TheyfoundthatthebirdsusedfivemigrationroutesacrossEurasia,probablyestablishedbetweenthelastIceAge22,000yearsagoandthemiddle-Holocene6,000yearsago.“PeregrinefalconsinitiatedtheirautumnmigrationmainlyinSeptember,andarrivedattheirwinteringareasmainlyinOctober,"saidProfessorMikeBruford,anecologistatCardiffUniversity.“Peregrinefalconsthatdepartfromdifferentbreedinggroundsusedifferentroutes,andwinteratwidelydistributedsitesacrossfourdistinctregions.Individualbirdsthatweretrackedformorethanoneyearexhibitedstrongpathrepeatabilityduringmigration,completeloyaltytowinteringlocationsandlimitedbreedingdispersal(扩散).”Theresearchersquantifiedthemigrationstrategiesandfoundthatmigrationdistanceisthemostsignificantdifferentiation.Theyusedwholegenomesequencingandfoundagene-ADCY8,whichisknowntobeinvolvedinlong-termmemoryinotheranimalsinpreviousresearch-associatedwithdifferencesinmigratorydistance.TheyfoundADCY8hadavariantathighfrequencyinlong-distancemigrantpopulationsofperegrinefalcons,indicatingthisvariantisbeingfavorablyselectedbecauseitmayincreasepowersoflong-termmemorythoughttobeessentialforlong-distancemigration.“Previousstudieshaveidentifiedseveralcandidategenomicregionsthatmayregulatemigration-butourworkisthestrongestdemonstrationofaspecificgeneassociatedwithmigratorybehavioryetidentified,”ProfessorBrufordsaid.Theresearchersfurtherlookedatmodelsoflikelyfuturemigrationbehaviortopredicttheimpactofglobalwarming.Iftheclimatewarmsatthesamerateasithasinrecentdecades,theypredictperegrinepopulationsinwesternEurasiahavethehighestprobabilityofpopulationdeclineandmaystopmigratingaltogether.“Ourworkisthefirsttobegintounderstandthewayecologicalfactorsmayinteractinmigratorybirds,”saidDr.ZHANXiangjiang.“Wehopeitwillserveasacornerstonetohelpconservemigratoryspeciesintheworld.”15．Whatcanwelearnfromthefirsttwoparagraphs?A．Fivebirds’historicalmigrationrouteswererebuilt.B．Peregrinefalconssticktotheareaswheretheywinter.C．Twonovelresearchmethodsofmigrationwereinvented.D．PeregrinefalconsleaveforArcticregionsinSeptember.16．WhatcanweinferaboutADCY8?A．Itisanewly-discoveredgeneinthenewstudy.B．Itservesasafundamentalpartoflong-distancemigration.C．Itcouldbestrengthenedbythepoweroflong-termmemory.D．Itturnedouttobemorefavoredbybirdsthantheotheranimals.17．Whatisspecialaboutthenewstudy?A．Ithasdiscoveredanewgenomicregionofbirds.B．Ithaspredictedtherateatwhichtheclimatewarms.C．Itanalysesthereasonsforthedecreaseofperegrinefalcons.D．Itencouragesattentiontoenvironmentaleffectsonmigratorybirds.18．Whichwouldbethebesttitleforthispassage?A．ResearchersHelpConserveMigratorySpeciesB．BiologistsFindEvidenceofMigrationGeneinBirdsC．HowLong-termMemoryHelpsLong-distanceMigrationD．HowEcologicalFactorsAffectBirds’MigratoryDistancesMicroplastics—

tinypiecesofplasticwastelessthanfivemillimetreslongthathavebeendegradedbywaves,windandultravioletrays—havebeendiscoveredinthedeepestoceanictrenchesandwithinthestomachsoftheorganismsthatlivethere,butwehavelittleideaaboutwherethegreatmajorityofthemendup.Morethaneightmilliontonnesofplasticentersouroceanseveryyear,comprisingbetween80and85percentofallmarinetrash,butwithinadequatedata,thereareconcernsthatthesefigurescouldbeunderestimates.Currently,mostofthedatawehaveonmicroplasticsareaccidentallycapturedbyresearchships,whichuseplanktonnetstocollectmarine-microorganismsamples.However,researchersChristopherRufandMadelineEvansfromtheUniversityofMichiganhavediscoveredaninnovativewaytoidentifyandtrackconcentrationsofmicroplasticsintheocean.ThetechniquereliesonNASA’sCycloneGlobalNavigationSatelliteSystem(CYGNSS),aconstellationofeightmicro-satellitesusedtopredicthurricanesthatcalculatewindspeedsabovetheoceanbymeasuringtheroughnessofsurfacewaters.Asthesatellitesarecontinuouslyrecording,RufandEvansrealisedthattheycollectagreatdealofadditionaldata.Itwaswhileanalysingthesedatathattheynoticedsomedifferences-timeswherethesurfaceoftheoceanappearedtobemuchsmootherthanitshould,giventheprevailingwind(盛行风)conditions.Knowingthatwaterisn’troughenedasmuchwhenitcontainsalotoffloatingmaterial,RufandEvansidentifiedapatternthatlinkedareasofunusualsmoothnessandpredictedmicroplasticdistributions.Theyfoundthatthedifferencebetweentheirmeasurements,andhowmuchrougherthesurfacewouldbeifwindsofthesamespeedwereblowingacrossclearwater,was“highlycorrelatedwiththepresenceofmicroplastics,andthedegreeofthedifferencealsocorrelatedwiththeconcentrationoftheplastics.”Theresearchrevealsthatthereareseasonalvariations,wheretheconcentrationsofmicroplasticstendtobehigherinthesummerandlowerinthewinterinaveryclean,periodicway,whichRufexplainsmirrorsthewayinwhichtheoceancirculationchangesthroughouttheyear.Italsoconfirms,aswaspreviouslythought,thatriversarethemainsourceofoceanmicroplastics.Raisingawarenessoftheissueofoceanmicroplasticsamongthepublicandpoliticiansisjustoneoftheresearchers’futureaims;theyarealsoinconversationwithDutehnon-profitTheOceanCleanupandFinnishclean-technologyspecialistClewat,whichareinterestedinusingtheinformationtomoreefficientlytargettheirtrash-collectioncampaigns.Sofar,onlyoneyear’sworthofdatahavebeenprocessedsinceCYGNSSwaslaunchedin2016.Bylookingatalongertimeperiod,RufandEvansaimtodeterminewhethertheseasonalpatternisrepeatable,andwhethertheconcentrationofmicmplasticsintheoceanisgettingworse.19．WhatisParagraph1mainlyabout?A．Thelimitedknowledgeaboutoceanmicroplastics.B．Theharmofoceanmicroplasticstoseacreatures.C．Themethodsofdegradingoceanmicroplasties.D．Thepreviousresearchonoceanmicroplasties.20．Accordingtothepassage,CYGNSS________.A．hasoffereddataabouttherepeatableseasonalpatternB．guidesresearchshipstogatherdataaboutseaanimalsC．providesunexpecteddataaboutthechangesofseasurfaceD．wasdesignedtomeasurethedistributionofoceanmicroplastics21．Whatcanwelearnfromthepassage?A．Microplasticswillendupinthestomachsoftheoceanorganisms.B．Mlicroplasticsplayavitalroleintheyearlyoceancirculationchanges.C．Thesurfaceoftheoceancangetsmootherwithmoremicroplasticsinit.D．Thenewwayoftrackingmicroplasticshashelpedpreventoceanpollution.22．Whatisthemainpurposeofthepassage?A．TointroducethetechnologyofCYGNSS.B．Topresentawaytostudyoceanmicroplastics.C．Totestanassumptiononoceanmicroplastics.D．Toproposeanewmeansofprotectingtheocean.Fewdishestastebetterthanajuicycutofbeef.Onesurveyin2014foundthatsteakwasAmericans’favoritefood.Unfortunately,bycookingsomanycows,humansarecookingthemselves,too.Theinfluenceoffoodongreenhouse-gas(GHG)emissions(排放)canslipundertheradar.InasurveyinBritainlastyear,theshareofanswererssayingthat“producingplantsandmeatonfarms”wasa“significantcontributor”toclimatechangewasthelowestamongtenlistedactivities.YettwopaperspublishedthisyearinNatureFoodfindthatfood,especiallybeef,createsmoreGHGSthanpreviouslythought.ThisMarchresearchersfromtheEuropeanCommissionandtheUN’sFoodandAgricultureOfficereleasedastudyestimatingthattheglobalfoodsystemwasresponsiblefor34%ofGHGin2015.Thepaperassignsthefullimpactofdeforestationtotheagriculturethatresultsfromit;includesemissionsafterfoodissold(suchasfromwasteandcooking);andcountsnon-foodcropslikecotton.Butevenwhentheauthorstookawayemissionsfromsourcesliketransportandpackaging,theystillfoundthatagriculturegenerated24%ofGHGS.Anotherrecentpaper,byXiaomingXuoftheUniversityofIllinoisandeightco-authors,allocates(分配)thisimpactamong171cropsand16animalproducts.Itfindsthatanimal-basedfoodsaccountfor57%ofagriculturalGHGS,versus29%forfoodfromplants.Beefandcow’smilkalonemadeup34%.Combinedwiththeearlierstudy’sresults,thisimpliesthatcattleproduce12%ofGHGemissions.Relativetootherfoodsources,beefisuniquelycarbon-intensive.Becausecattleemitmethane(甲烷)andneedlargegrasslandsthatareoftencreatedbycuttingmoreforests,theyproduceseventimesasmanyGHGSpercalorieofmeataspigsdo.Thismakesbeefabiggershareamongfoodsthancoalisamongsourcesofelectricity.Thesimplestwaytocutbeefoutputisforpeopletoeatotheranimalsinstead,orbecomevegetarians.Butconvincingpeopletogiveuptheirburgersisatallorder.Fortunately,lab-grownmeatsaremovingfromPetridishes(培养皿)tohigh-endrestaurants.Doingwithoutbeeffromlivecattleishardtoimagine,butthesamewastrueofcoal100yearsago.Lab-grownmeatcouldplayanessentialroleinslowingaclimatedisaster.23．Theunderlinedphraseinparagraph2canprobablybereplacedby____________.A．bedetectedbyradar B．beignoredbypeopleC．beexplainedbyexperts D．becontrolledbygovernment24．Whatcanwelearnfromthepassage?A．Lab-grownmeatswillreplaceothermeatsinthefuture.B．QuittingsteakmaybeanefficientwaytoreduceGHG.C．ProducingbeefgeneratesmoreGHGthanburningcoal.D．BeeftransportisthemajorcontributorofGHGemissions.25．Theauthormentionsthecoalinthelastparagraphjusttoshow____________.A．theimportanceofbothlab-grownbeefandcoal B．thedifficultytoproducethelab-grownmeatC．thenecessityofbeeffromlivecattle D．thefutureoflab-grownbeefDeepSea:ToMineOrNotToMineArobotaslargeasatruckmovesalongthebottomofthedeepsea.Iteatsmetallic(含金属的)rockandsoftmud.Theytravelupalongpipetoaship,whereworkersandmachineryseparateouttherockandthrowthemudbackintotheocean.Thisisaminingoperation.Therockcontainsamixtureofmetals,includingonescalledrareearthmetals.Peopleusethesematerialstomakebatteriesandelectronicslikecomputersandphones.Deep-seamininghasn’thappenedyet.Butitprobablywilloccurwithinthenextdecade.Nocountryownsanypartofthedeepsea,soaUNorganizationcalledtheInternationalSeabedAuthority(ISA)decideswhoisallowedtominethere.Ithasallowed29organizationstoexplorethedeepseaandmakeplansformining,oneofwhichplanstobeginminingintheyear2027.Scientistsandenvironmentalists,though,warnthatminingcoulddestroydeep-seaecosystem.In1989,ecologistHjalmarThielcarriedoutatest.HisteamsearchedtheseafloorofthePacificOcean,inaspotwithlotsofthemetallicrocksthatminerswanted.Theydidn’tactuallycollectanyoftherocks.Buttheydisturbedthemud,justasaminingoperationwould.Thecloudofmudfellbackdownovertheoceanfloorburyingcreatureslivingthere.Uptonow,theareatheydisturbedhasnotrecovered.Signsofthesearcharestillthere.Deepseacreatureslikespongesandcoralshavenotmovedbackin.Thatmeansminingcouldhaveharmful,long-lastingconsequencesford