2020牛津譯林版高中英語選修一課文原文Unit1OurlivingplanetTheoceandeepWelookupwardsandwonderwhatliesbeyondourplanet.Wesendprobesintothevastnessofspacetoexploretheunknown.Webuildspacestationstoadvanceourunderstandingoftheuniverse.Ourcuriosityaboutouterspacehasremainedunshakable.Meanwhile,itisestimatedthatmorethaneightypercentoftheworld'soceansareunexplored.So,ifwewanttofindexcitingnewlifeformsaswellasundiscoveredandunusualgeologicalformations,theoceaniswhereweshouldalsobelooking·Thenwhydon'twedivetothebottomofareallydeepoceanandtakealong,closelookbeneaththewaves?Thefirst200metresofourdivetakesusthroughwhatcanbecalledtheopenocean,wheremostvisiblelightexists.Herelivesmuchofthemarinelifeweknowabout,suchasdolphins,coralsandseaweeds.Sinkingbelow200mertes,weenterthetwilightzone,wherethereislittlesunlightandthusalmostnoplantlife.Mostofthefishlivingherearesmallfilterfeederswhichswimupatnighttofeedinthenutrient-richwatersabove.Alsolivinginthetwilightzonearehunterswithtelescopic,upward-pointingeyesthatcaneasilyspotamealinthewatersabove.Consequently,thefishmostlikelytobeeatenhaveevolvedtohavethinbodiessothartheyarclesseasilytobeseenfrombelow.However,oncetheyarecaptured,thehunters’backward-carvingteethpreventthemfromgettingaway.Evolution,itseems,helpsboththehunterandthehuntedinequalmeasure.Oncepast1,000metres,wehavereachedthedeepocean,wherethereisnolightandtemperaturesdropjustabovefreezing.Thepressuresarehugeandcanbemorethan100timesthepressureoftheEarth’satmosphere.Itisthensurprisingthatmanycreaturescanliveinthisextremeenvironment.Theycannotrelysolelyontheireyesighttosurviveandhaveevolvedfascinatingcharacteristics.Indeed,manyorganismsinthedeepoceanareblind.Inordertoobtainfoodandavoidbeingcaught,theyhavetodependonothersensessuchassmellandtheirabilitytodetectslightchangesinwaterpressure.Also,somefishhavebothmaleandfemaleorganstoincreasethechancesofreproduction,asfisharesoscarceatthesedepthsthatitcanbedifficultforthemtofindamate.ThefishinthedeepoceanareamongthestrangestcreaturesontheEarth,manyofwhichhaveyettobeproperlystudied.Onreachingtheoceanfloor,wemayseeshrimpsandotherorganismsaroundhydrothermalvents.Theseventsforminvolcanicallyactiveareas,pouringmineral-richfluidsintothesea.Beforethediscoveryofthesecreatures,itwasthoughtthatalllifeontheEarthobtaineditsenergyfromthesun.However,thisdiscoveryhasrevealedthatlifeformscanobtainnutrientsandenergyfromthermalsources.Knowingthatlife35canexistintheseextremeconditionshaschangedscientificopinionaboutthechancesoftherebeinglifeelsewhereintheuniverse.Inadditiontotheventsandremarkableorganisms,wecannotmisstheMarianaTrench,locatedinthenorth-westernpartofthePacificOcean.Itsdeepestpoint,knownastheChallengerDeep,isnearly11,000metresbelowsealevel.YoucouldplaceMountQomolangmaintheChallengerDeep,anditstopwouldstillbemorethan2,000metresbelowthesurface!Whilethereislittlelifeatsuchgreatdepths,itisfarfromboring.OfthemanystrangegeologicalformationstobefoundherearerockbridgeswhichcrosstheTrench,somereachingaheightof2,500metresabovetheChallengerDeep.Asyoucansee,theworldbeneaththesurfaceoftheoceanisindeedanamazingplace.45Onourjourneydown,wehavebeenfascinatedbyincrediblegeologicalformationsaswellasunexpectedlifeformsthathavebecomestrangelyadaptedtotheirextremeenvironment.Withsomuchoftheoceanslefttoexplore,whoknowswhatwondersstillawaitusinthefuture?ExtendedreadingReadthearticleandcomicstripfromasciencemagazineabouttheinsideoftheEarth.InsidetheEarthHaveyoueverwonderedwhatliesbeneathyourfeet?Idon'tmeanthefloorofyourapartment,orthepavementyouwalkon,butratherwhattheEarthisactuallymadeof.Unfortunately,wecannotcracktheEarthopenlikeanegg,s0muchofwhatscientistsknowabouttheEarth'sinternalstructureisbasedonanalysingearthquakewaves.TofindoutmoreabouttheEarth'smake-up,scientistshavedrilledverydeepholesbutnonehavereachedthemantleasyet.TheintensepressureandheatinsidetheEarthcancloseupadeepholeorbreakadrill.Choosingtherightplacetodrillisalsonoteasy.However,withinafewyears,scientistsarehopingtodrillintothemantle,whichwillhelpusbetterunderstandthegeologyoftheEarth.StudyingtheinsideoftheEarthhasotherbenefitstoo.Somescientistsarelookingatexcitingpossibilitiesforlifeaboveground.Ithasbeendiscoveredthatundercertainextremeconditionsofpressureandtemperature,waterformsicecagesthattraphydrogeninside.Thismayhelpsolvethestorageproblemofhydrogenandpavethewayforcarstorunonhydrogenfuel.OtherscientistshopethatresearchintomicroorganismsdeepinsidetheEarthwouldcastlightontheoriginoflife.Almosteverylivingthingonourplanetdependsonenergyfromthesun.However,themicroorganismsinagoldmineofSouthAfricasurvivewherethesunnevershines,relyingonenergyfromcertainrocks.Therefore,iflifeontheEarthcansurvivedeepundergroundwithoutsunlight,couldlifealsobethrivingbeneaththesurfaceofMars?Thenexttimeyoutakeawalk,thinkabouttheimportanceofwhatliesbeneathyourfeet.Surely,astudyoftheinsideofourplanetwouldleadtoexcitingandenlighteningdiscoveries,andbenefitallwhowalkuponit.Crust:athinlayerofrockontheEarth'ssurfaceMantle:rockbelowthecrustandsurroundingthecoreCore:extremelyhot,liquidironmixedwithotherhot,slow-movingcomponents,coveringasolidcentre,whichistheinnermostpartoftheEarthJourneytothecentreoftheearthWhatmightwefindifwecoulddigintotheground,andmakeafantasticjourneytothecentreoftheEarth?Manhaswonderedaboutit,writtenaboutitandmadefilmsaboutit.Whydon'twegodown,down,down……withabucketandSpadetofindout?4metresTherearenomoreearthworms.122metresWeleavebehindthedeepestknowntreerootsofthewildfigtreeofSouthAfrica.2.400metresThedeepestundergroundlaboratory,atJinping,,China,ispassed.30,000metresWearenowattheboundarybetweentheEarth'scrustandthemantlebelow.Herethepressureislike131elephantformingatoweronourhead!150,000metresWeareattheplacewherediamondswereformedbetween1and3billionyearsagoandthensweptuptothesurface.750,000metresWehave1achedthelowermantleandhave3,2280elephantsstandingonourhead!2.9millionmetresWeareabouttoheadintotheEarth'score.Wenowhaveabout17,000elephantsbalancedonourhead!6millionmetresWehavereachedourobjective.WearenowatthecentreoftheEarthwithover47.000elephantsonourhead!Butnottoworry,it'sover6,000ChereandSowewereallcookedalongtimeago!Unit2WorkingthelandReadingPrecisionfarminghitsitstargetWhenwethinkoffarming,thefirstimagethatspringstomindmightbeofafarmerworkinginafieldunderthebakingsun.Facecoveredinsweat,hemightbewalkingthroughthefield,carefullycheckinghiscropsbeforedecidingwhatneedstobedone.Inmoderntimes,however,thisdeep-rootedimageofatraditionalfarmerisbeingchanged.Thecollaborationbetweenfarmingandtechnologyhasgivenrisetoprecisionfarming,anapproachthatequipsfarmerswiththetoolsanddatatheyneedtomakereliabledecisionswithremarkableaccuracy.Thisevolutionishavingapositiveimpactonfarming,whilealsoprovidingbettersolutionstotheworld'spressingfoodproblems.Itistheadventofmoderntechnologythathasturnedfarmingintoahighlypreciseindustry.Thislatestwaveofinnovationoffersfarmersinformationthatismoredetailed,measurementsthataremoreaccurateandsolutionsthataremoreeffective.Therefore,precisionfarmingisadata-drivenapproachtotheimprovementoffoodproductionwiththeprimarygoalsofreducingafarm'sinput,increasingitsoutputandbetterconservingtheenvironment.Thesegoalscanbeachievedwithacombinationofinformation-gatheringtoolslikesensors,satellitesanddrones,andadvancedtechnologiessuchasartificialintelligence(Al).Withmassiveamountsofdataonthestateoftheirfarmlandgathered,analysedandprocessedinrealtime,farmersareabletogivethebestpossiblecaretothecropsthatmostneeditatthemostappropriatetimeandputtheirresourcestothebestuse.Asanaddedbonus,thedeclineintheamountofunnecessarychemicalsminimizespotentialthreatstotheenvironment.Precisionfarmingboastsadiverserangeofapplicationcapabilitiesatdifferentstagesoffoodproduction-monitoring,diagnosing,identifyingandtargeting.Soilsampling,anexampleofprecisionfarminginitsmostfundamentalform,providesanaccuratemeansforfarmerstotendtheircrops.Fieldsensorscheckthesoil'smoisture,nutrientlevelsandpHlevels,enablingfarmerstomonitortheircropsatanytime,fromanywhere.Asthedatalibrarybuildsup,"abigpicture"ofthesoilisrevealedsothatfarmersareabletoaccuratelyassesstheconditionofthesoilinrealtime,identifypotentialproblemsandworkoutsolutionsaccordingly.Forinstance,ifthesoilisfoundtobepoorinnutrients,notonlydofarmersknowthatfertilizerisneeded,theycanalsocalculatetheexactamount.Consequently,soilsamplingmakesitpossibleforfarmerstocreatetheidealconditionsfortheircropstogrowandmanagetheirresourceseffectivelyatthesametime.Whilesuchapplicationsareofenormousbenefit,precisionfarmingcanreachamuchhigherlevelwiththeapplicationofartificialintelligence.Whenusedinfarmingmachines,AIdoescontributetoincreasedcropyieldsaswellassimplifiedcroptracking,harvestingandprocessing.AI-controlledmachinescannowplantandharvestmorecropsatfasterspeedsthanhumansevercould,whilecomputervisioncandistinguishweedsfromcrops.Moreover,algorithmsbasedondatagatheredbysensors,dronesandsatellitescanworkoutsite-specificmanagementofthecrops.Withsuchefficiencyandaccuracy,thistechnologyisidealforfarmingcropsthatrequiredelicatehandling.Forexample,cottonfarmersusedroneswithAItechnologytocarryoutspecializedtasks:theypreciselyremovethecottonplants'leavesbysprayingchemicalsonlyonthepartsthatneedthem.Thedronesautonomouslynavigatethefields,takingimagesofthecrops,whicharethenanalysedbysoftware.Oncetheexactamountneededisdetermined,thedronesspraythechemicals,whilefarmerscanfollowthewholeprocessonamobiledevice.

Thankstoprecisionfarming'scloserelationshipwithtechnology,thefarmingindustry'scapabilitiescandevelopevenfurther.Throughtheintegrationof5GtechnologyandtheInternetofThings(loT),aswellasadvancesindeep-learningtechnologies,notonlywilllargeramountsofdatabeavailable,buttheywillbeprocessedmoreefficiently.Consequently,precisionfarmingwillbecomemoreeffectiveandhaveanevengreaterimpactonhowwegrowourfood.Withoutdoubt,thepushforfuturedevelopmentsinprecisionfarmingwillbenefitallofus-itwillcontributetoagreener,healthierandbetter-fedplanet.Extended

readingTea:China’sgifttotheworldTeaiscurrentlytheworld'smostpopulardrink,onlyafterwater.However,therewasatimewhenteawasknownonlytotheChinese.So,howdidteaoriginateinChina?Andhowdiditgettoconquertheworldtotheextentthatpeopleoftendescribesomethingtheyreallylikeastheir"cupoftea"?WhileweknowthatteadrinkingstartedinChina,itstrueoriginremainssomethingofamystery.Legendhasitthatabout5,000yearsago,Shennongcameacrossteawhendriedleavesblewintoapotofboilingwater.Followinghisdiscovery,teawasusedasmedicine,includedinmealsandlaterofferedasarefreshingdrinktoofficialsandnoblemen.Eventually,itbecameacommondrinkenjoyedandembracedbyallChinesepeople.Overtheyears,asteadrinkingbecameanimportantpartofChina'srichculture,theloveofteainspiredmanypeopletowriteaboutit.ThegreatTangpoetDuFudescribedhistea-drinkingexperienceinpoeticlanguage,"Onthehighplacethesettingsundoesshine.Inthespringbreeze,Isipmytea,sweetandfine."LuYu,ateamaster,wroteTheClassicofTea,whichremainstheearliestandmostfamousdetailedstudyonteaintheworld,coveringeverythinganyonecouldpossiblywanttoknowaboutChinesetea.Itisthennotsurprisingthatthebeautyofteawaseventuallyrevealedtoawiderworld.WhentheTangandSongDynastiesneededstrongTibetanhorses,theTeaHorseRoadwasborn.Porterscarryingback-breakingloadsofteabricksmadetheirwaythroughdangeroussnow-coveredmountainpassesinthemostterribleweatherconditions,totradeSichuanandYunnanteaforhorses.Overtime,thegiftofteawasfurtherdeliveredtoWesternAsiaandEasternAfrica.Meanwhile,differentsearoutesalsohelpedspreadteatootherpartsoftheworld.AsearlyastheTangDynasty,JapanesemonkscametostudyinChinaandtookwiththemteaseedsandtea-makingcustomswhenreturningtoJapan.Aroundthe1600s,teawasshippedtoEuropefromChinabyPortugueseandDutchseatraders.Thewell-knownwriterLinYutangsummedupthepowerofteawhenhesaid,"Thereissomethinginthenatureofteathatleadsusintoaworldofquietcontemplationoflife."Teadrinkingisnotjustaboutrefreshingthemindandbodybutalsoaboutappreciatingtheharmonybetweenmanandnature.FromhillsidetoteacupGrowingteaTeaplantsgrowbestinwarm,humidregionswithwell-drainedsoil.Consequently,theygrowwellonsteephillsideswhereheavyraincaneasilydrainaway.Chinaboastsmanytea-growingareas,whichcanbedividedintofourdistinctregions.Amongthemthesouth-westtea-growingregionistheoldestwhiletheregionsouthoftheYangtzeRiverproducesthemostteainChina.[Subheading1]_________Teabushesaregrowninrowsandcuttoaheightofaboutonemetre,toallowteapickerstoeasilyharvesttealeaves.Ittakesuptofiveyearsforateabushtocometomaturity,atwhichtimethebudandtopleavesarepickedeveryfewdays.Thetea-pickingseasonmaystartasearlyasFebruaryandextenduntillateNovember.[Subheading2]________Theprocessofturningtealeavesintotheteawelovetodrinkisbothcomplicatedandhighlytechnical.Therearecommonlybetweentwoandsevenproceduresinvolvedintheprocessingofthefreshtealeaves.Anyadditionorexclusionofthesestagesresultsinadifferenttypeoftea:green,yellow,white,blackandoolongtea.Actually,allthesedifferenttypesofteacanbemadefromasingleteaplant.[Subheading3]_________Teacanbeenjoyedinmanydifferentways.Forexample,theEnglishdrinktheirteawithmilk,theJapaneseenjoypowderedgreentea,andinMorocco,mintteaispreferred.Teadrinkinghasalsobecomepartofmanycountries'culture.TheEnglishhavetheir"afternoontea",andinChina,rightfullyregardedasthe"birthplace"oftea,teadrinkingcanbebothacommondailypracticeandanearceremonialexperience.Unit

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Self-drivingcars—destinationknown?MrZhangcasuallyglancesattheemptydriver'sseatandsays,"DestinationGrandHotel.Familymode.Start."Thecarrespondsimmediately,easingsmoothlyintothebusytrafficandavoidingobstaclesontheroad.Insidethecar,thefamilyhavechosentheirentertainmentfromapop-updisplaypanel,readyforthejourneyahead.Thisimaginedsceneprovidesalikelyfuturerealityforself-drivingcars,alsoknownasautonomousvehicles(AVs).However,beforethisevolutionintransportbecomesarevolution,itmustbefullyunderstoodhowself-drivingcarswork.Putsimply,self-drivingcarsmust"see"and"behave"appropriatelytobesafeontheroad.Theydothisthroughvarioushardwareanddeep-learningAI.Camerasaswellassensorslikeradarandlidarcaptureavarietyofdatafromtheexternalenvironment.OncethedataissenttotheAIsystem,the"brain"ofthecar,itisanalysedandputtogetherlikeapuzzlesothattheself-drivingcarcan"see"itssurroundingsanddetermineitsposition.Meanwhile,theAlsystemidentifiespatternsfromthedataandlearnsfromthem.Anactionplanisthencreatedtoinstructthecarhowto"behave"inrealtime:stayinthelane,moveintoanotherone,speeduporslowdown.Next,thenecessarymechanicalcontrols,suchastheacceleratorandbrakes,areactivatedbytheAIsystem,allowingthecartomoveinlinewiththeactionplan.Thismaysoundperfectintheory,butinrealitytechnologicalbarriersinAVdevelopmentexist.Theself-drivingcar'sperceptionsystempresentsone.Roadtrafficintherealworldissocomplicatedthatunfamiliarorunexpectedconditionsmayoccuratanytime.Sinceitisunreasonableforthedatabasetoincludeeverypossibleobjectineverypossibleconditionaheadoftime,thesystemmightnotrecognizeeverythingontheroad.Inonetragicreal-lifecase,aself-drivingcar'sperceptionsystemfailedtoidentifyawhitetruckagainstthebright,sunlitsky.Itassumedthattherewasnoobstacleinitspathanddidnotactivatethebrakes,causingthedeathofthedriverintheself-drivingcar.Accidentslikethisposethequestionofhowself-drivingcarscanbetterlearnandimprovetheirbehavioursontheroadtoensuresafejourneys.Anotheraspectthatneedscarefulconsiderationistheethicalresponsesself-drivingcarswouldmakeinspecificcircumstances.TheTrolleyProblemisoftenusedtodiscussdifficultethicalchoicestheymayface.Forexample,shouldthoseintheself-drivingcaralwaysbeprotectedfirstevenifitmeansendangeringthelivesofpedestrians?Shouldaself-drivingcarhitasinglepedestriantoavoidcrashingintoagroupofpedestrians?Andwoulditmakeadifferentdecisionifthepedestrianwereachildoraseniorcitizen?Themoraldilemmathatcomeswithhowtoethicallyprogramself-drivingcarshasyettoberesolved.Besidessuchethicalconcerns,thelegalsituationstheAVindustryislikelytobeconfrontedwithhavefuelledheateddebates.Inthisemergingindustry,manufacturingandprogrammingstandardsarenotyetuniform.Moreover,thequalityandsafetyofAVtechnologyisstillbeingchallenged.Thiscouldleadtoextraordinarycaseslikewhoshouldbeheldresponsiblewhenself-drivingcarsareinvolvedinaccidents-shoulditbethedriver,thesoftwareprogrammerorthemanufacturer?Manufacturingandprogrammingstandardsfirsthavetobeagreedupontomakeitpossibleforlawcourtstodecidewhoisatfaultwhenthingsgowrong.AsadvancesinAVdesignandtechnologyareinprogress,thefinalagreementonlawsandregulationsinthisindustryremainstobeseen.Therecanbelittledoubtthat,despiteallthechallenges,self-drivingcarswillformpartofourfuture.Thequestionis,whatisnext?Somearguethatself-drivingcarsshouldbeallowedtooperatewithouthumancontrol,whileothersaremorecautiousandbelievethathumanoperation,eveniflimited,isnecessaryinsuccessfulAVdesign.Onlytimewillrevealitstruepath.Whilethejourneyaheadisnotwithoutobstacles,theeventualdestinationisboundtobeanothermilestoneforhumankind'samazingvisionandinventiveness.Extended

readingRacingtowardsthefuture:alookatChina’shighspeedrailnetworkInthedistance,awhitebullet-nosedtrainisthunderingdownthetrack.Itgrowslargerbytheseconduntiliteventuallyslowsandglidespastthelinesofwaitingpassengers.Asiteasestoastop,itsdoorsopenwithahissandthepassengersboardwitheageranticipation.Thenthedoorscloseandthetraindepartsexactlyontime,itsprogressbarelynoticedasitquicklyandsilentlygathersspeed.Seatedcomfortablyinthewell-equipped,spaciouscarriages,thepassengersknowthattheirjourneyaheadwillbebotheffortlessandrelaxing.SuchscenesofcontentedpassengersbeingswiftlytransportedtotheirdestinationsarerepeatedmanytimesadayalloverChina,asfarasthehigh-speedrail(HSR)networkextends.Since2008,theHSRnetworkhastransportedover10billionpassengers,settingaworldrecord.Therearenowmorethan3,000high-speedtrainsrunningdaily,somereachingspeedsofupto350kilometresperhour,thefastestintheworldoftraintransport.Alreadycovering92percentofcitieswithpopulationsthatexceedhalfamillionasof2020,theHSRnetworkreacheseverycornerofthecountry.Withanoveralllengthofaround40,000kilometresinoperation,itnotonlygreatlyenhancesthenationalrailroad'sefficiency,butalsoservesastheenginethatkeepsthecountry'seconomiclifebloodflowing.However,China'shigh-speedrailnetworkwasnotbuiltovernight.TheHSRprojectbeganinthe1990sandithasgrownenormouslysincethen.AkeymilestonewasthereleaseoftheHSRnetworkblueprintin2004,whentheplanfor"fourverticalandfourhorizontal"corridorswasputforward.Twelveyearslater,itwasupgradedto"eightverticalandeighthorizontal"corridors.Today,Chinaboaststheworld'slongestandmostextensivelyusedHSRnetwork,andisrightlyconsideredtheworldleaderinHSRconstruction.ThisenormoussuccessisinseparablefromthevisionaryleadershipoftheCommunistPartyofChinaaswellasthegreatwisdomoftheChinesepeople.Withinnovationandperseverance,theyhaveclimbedoverhurdlesandpassedonemilestoneafteranother.TheBeijing-Shanghailine,theworld'slongestlinebuiltinonestage,hasthefastesthigh-speedtrains,reducingthetraveltimebetweenBeijingandShanghaifrom14hourstolessthan5hours.TheHarbin-Dalianline,thefirsthigh-coldhigh-speedrailwayintheworld,canoperateat350kilometresperhourintemperaturesaslowas-40℃.TheBeijing-Zhangjiakouline,theworld'sfirstsmarthigh-speedrailway,hassetthestandardforHSRautomaticdriving.TheFuxingElectricMultipleUnit(EMU),whichmadeitsdebutin2017,isanotherremarkableaccomplishmentthatdemonstratestechnicalskillinHSRdesignandconstruction.DevelopedandmanufacturedtotallybyChina,theEMUtrainboastsmodernizedfeatures,elegantdesignsandadvancedtechnologiesthataresuperiortothoseofpreviousmodels.Itisbuiltwithalongerlifespanandanenergy-savingdesigntoreduceairresistance.Alltheseachievementsshowcasethewholehearteddevotionofengineers,thetirelesseffortofrailroadworkers,andthestrongsupportofalltheChinesepeople.ItisnosurprisethenthatChina'sHSRnetworkhasgrabbedtheattentionofthewholeworld.Inthespiritofinternationalcooperation,Chinahasgenerouslyexporteditstechnologyandskillstomanycountries,andhelpedthemconstructhigh-speedrailwaylines.ThisisinlinewiththeBeltandRoadInitiative,whichaimstorevivetheancientSilkRoadandconnectthecountriesalongtheroute.TheWorldBankhaspraisedChina'sHSRsuccessanditspositiveimpactswhichgowellbeyondtherailwaysectortoincludeurbandevelopment,regionaleconomicgrowthandreductionsingreenhousegasemissions.TheHSRnetworkhasbecomeanewsymbolofChina,and"ChinaStandard"hasbecomethe"WorldStandard".Inthepast/Lookingback,theHSR'spathwasfilledwithobstaclesandachievements.Racingtowardsthefuture,China'sHSRnetworkwillcontinuetogrow,improvingthelivesofitspeopleandstrengtheningunityamongthem.Now,itisshiningabrightlightonthetrackaheadtoevengreatersuccess.So,sitbackandenjoytheride!Unit4

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scienceReadingThehumanmicrobiome:aninvisiblemicrouniverseWhatorganismslivewithus,makeupabouttwopercentofanadult'sbodymass,yetareinvisibletothenakedeye?Theyaretheestimated39trillionmicroorganismslivinginandonourbody,likebacteriaandviruses,whichcomposethehumanmicrobiome!Butthereisnoneedtopanic,formostofthemaretheretokeepushealthy.Eventhoughincrediblysmall,thesemicroorganismsinfluenceourbodyandmindinbigunexpectedways.So,wheredothesemicroorganismscomefrom?Well,theyhavealwaysbeenapartofus.Ourveryfirstbirthdaygift-threequartersoftheessentialmicroorganismsweneedtosurviveandgrow-isfromourmotherwhenweareborn.Bythetimewereachtwoyearsold,wehaveourveryownpersonalcollectionofmicroorganismsthatreflectsthevariouscircumstancesofourlives.Goingthroughlife,wefurtherexposeourselvestoforeignmicroorganisms,whichcauseapartofourmicrobiometochangeeveryday.However,ourcoresetofmicroorganisms,approximatelytwothirds,staysfairlyconstantthroughoutourlives.Themake-upandstateofourspecialblendofmicroorganismsaffectsusphysically,includingourimmunesystem,weightandsleeppatterns.Everyday,theresidentmicroorganismsinourbodiescompetewiththeinvadingones,preventingthemfromgettingafoothold,thushelpingformastrongimmunesystemandkeepushealthy.Similarly,thecompositionofourgutmicrobiomeplaysavitalroleinregulatingourbodyweight.Besideshelpingdigestfood,evidenceindicatesthatgutmicroorganismsaffectthewaywestorefatandrespondtochemicalsthatmakeusfeelhungryorfull.Asaresult,withoutthepropermixofmicroorganismsinthegut,wemightsufferfromhealthproblemslikeobesity.Addedtothis,microorganismscaninfluencecertainaspectsofoursleeppatterns.Ifwestayupallnightortravelrapidlythroughmanytimezones,wemayinterruptthemicroorganisms'biologicalschedules,whichislikelytocauseadisturbanceinournormalsleeproutine.Theinfluenceofmicroorganismsreachesbeyondphysicalhealthtoourcognitiveandpsychologicalwell-being.Believeitornot,gutmicroorganismsaffecthowwellthebrainfunctions.Whilescientistsarestillattheearlystagesofuncoveringexactlyhowgutmicroorganisms