2013年职称英语理工类abc3套真题

2013年英语理工TherulesaretoorigidtoallowforhumaneA. B. C. D.ThisspecieshasnearlydiedoutbecauseitshabitatisbeingA.turned B.passed C.carried eexThecontractbetweenthetwocompanieswillexpireA. B. C. D.Threeworld-classtennisyerscametocontendforthisA. B. C. D.ThemethodsofcommunicationusedduringthewarwereA. B. C. D.RespectforlifeisacardinalprincipleoftheA. B. C. D.Thedrinkingwater econtaminatedwithA. B. C. D.Comeout,orI’llbustthedoorA. B. C. D.Sheshedafewtearsatherdaughter’sA. B. C. D.Theydidn’tseemtoappreciatethemagnitudeoftheA. B. C. D.ThetowerremainsintactevenaftertwohundredA. B. C. D.ManyexpertsremainskepticalabouthisA. B. C. D.TheproposalwasendorsedbythemajorityofA. B. C. D.RumorsbegantocirculateabouthisfinancialA. B. C. D.ThewillneedtokeepawaryeyeonthisareaofA. B. C. D.NewUnderstandingofNaturalSilk’sNaturalsilk,asweallknow,hasastrengththatman-madematerialshavelongstruggledtomatch.Inadiscoverythatsoundsmorelikeanancientproverbthanamaterialssciencebreakthrough,MITresearchershavediscoveredthatsilkgetsitsstrengthfromitsweakness.Or,morespecifically,itsweaknesses.Silkgetsitsextraordinarydurabilityandductility柔韧性)fromanunusualarrangementofhydrogenbondsthatareintrinsicallyveryweakbutthatworktogethertocreateastrong,flexiblestructure.Mostmaterials especiallytheonesweengineerforstrength gettheirtoughnessbrittleness.Assuch,naturalsilkslikethoseproducedbyspidershavelongfascinatedbothbiologistsandengineersbecauseoftheirlightweight,ductilityandhighstrength(poundforpound,silkisstrongerthansteelandfarlessbrittle).Butonitsface,itdoesn'tseemthatsilksshouldbeasstrongastheyare;molecularly,theyareheldtogetherbyhydrogenbonds,whicharefarweakerthanthecovalent共价的)bondsfoundinothermolecules.Togetabetterunderstandingofhowsilkmanagestoproducesuchstrengththroughsuchweakbonds,theMITteamcreatedasetofcomputermodelsthatallowedthemtoobservethewaysilkbehavesattheatomiclevel.Theyfoundthatthearrangementofthetinysilknanocrystals纳米晶体)issuchthatthehydrogenbondsareabletoworkcooperatively,reinforcingoneanotheragainstexternalsandfailingslowlywhentheydofail,soasnotsoallowasuddenfracturetospreadacrossasilkstructure.Theresultisnaturalsilksthatcanstretchandbendwhileretainingahighdegreeofstrength.Butwhilethat'sallwellandgoodforspiders,beesandthelike,thisunderstandingofsilkgeometrycouldleadtonewmaterialsthatarestrongerandmoreductilethanthosewecancurrentlymanufacture.Ourbestandstrongestmaterialsaregenerallyexpensiveanddifficulttoproduce(requiringhightemperaturetreatmentsorenergy-intensiveprocesses).Bylookingtosilkasamodel,researcherscouldpotentiallydevisenewmanufacturingmethodsthatrelyoninexpensivematerialsandweakbondstocreatelessrigid,moreforgivingmaterialsthatarenonethelessstrongerthananythingcurrentlyonoffer.Andifyouthoughtyouweregoingtogetoutofthismaterialssciencestorywithouthearingaboutcarbonnanotubes(纳米碳管),thinkagain.TheMITteamisalreadyinthelablookingintowaysofsynthesizingsilk-likestructuresoutofmaterialsthatarestrongernaturalsilk—likecarbonnanotubes.Super-silksareontheMITresearcherscarryoutthestudytoillustrateanancient B. C.NotSilk’sstrengthcomesfromitsweakhydrogenbondsworking B. C.NotBiologistsandengineersareinterestedinunderstandingnaturalsilksbecausetheyareverylightand B. C.NotIfthehydrogenbondsbreakduetoexternals,theybreak B. C.NotTheMITteamhadtrieddifferentmaterialsbeforetheystudiesnaturalsilkinthe B. C.NotCarbonnanotubesarecurrentlythemostpopulartopicinmaterials B. C.Not B. C.NotBlackBlackholescanbebestdescribedasasortofvacuum,suckingupeverythinginspace.Scientistshavediscoveredthatblackholescomefromanexplosionofhugestars.Starsthatareneardeathcannolongerburnduetolossoffuel,andbecauseitstemperaturecannolongercontrolthegravitational(重力的),hydrogenendsupputtingpressureontothestar’ssurfaceuntilitsuddenlyexplodesthenBlackholescomefromstarsthataremadeofhydrogen,othergasesandafewmetals.Whentheseexplodeitcanturnintoaslar-mass(恒星质量)blackhole,whichcanonlyoccurifthestarislargeenough(shouldbebiggerthanthesun)fortheexplosiontobreakitintopieces,andthegravitystartstocompacteverypieceintothetiniestparticle.Trytoseeandcompare:ifastarthat’stentimesthesizeofthesunendsupbeingablackholethat’snolongerthan70kilometers,thentheEarthwould eablackholethat’sonlyafractionofaninch!Objectsthatgetsuckedinablackholewillalwaysremaintherenevertobreak.Butrememberthatblackholescanonlygobbleup(吞噬)objectswithinaspecificdistancetoit.It’spossibleforalargestarnearthesunto eablackhole,butthesunwillcontinuetostayince.Orbitsdonotchangebecausethenewlyformedblackholecontainsexactlythesameamountofmassaswhenitwasastar,onlythistimeitsmassistotallycontractedthatitcanendupasnobiggerthanastate.Sofar,astronomershavefiguredoutthatblackholesexistbecauseofAlbertEinstein’stheoryofrelativity.Intheend,throughnumerousstudiestheyhavediscoveredthatblackholestrulyexist.Sinceblackholestraplightanddonotgiveofflight,itisnearlyimpossibletodetectblackholesviaaescope.Butastronomerscontinuetostudygalaxies,spaceandthesolarsystemtounderstandhowblackholesmightevolve.Itispossiblethatblackholescanexstformillionsofyears,andlatercontributetoabiggerprocessingalaxies,whichcaneventuallyleadtocreationofnewentities.Scientistsalsocreditblackholesashelpfulinlearninghowgalaxiesbegantoform.IsthereIsthereproofthatblackholesreallyWhataredifferenttypesofblackHowareblackholesHowwereblackholesWhathappenstotheobjectsaroundablackWhatareblackholesmadeParagraphParagraphParagraphBlackholesareformed Whenalargestarexplodes,thegravitycompactseverypiece Anewlyformedblackholeandthestaritcomesfromare AlbertEinstein’stheoryofrelativityhelpsto thecreationthecreationofnewanexplosionofhugethetiniestthesameamountoftheexistenceofblackafractionofan第一篇ForecastingThereareseveraldifferentmethodsthatcanbeusedtocreateaforecast.Themethodaforecasterchoosesdependsupontheexperienceoftheforecaster,theamountofinformationavailabletotheforecaster,thelevelofdifficultythattheforecastsituationpresents,andthedegreeofaccuracyorconfidenceneededintheforecast.Thefirstofthesemethodsisthepersistencemethod;thesimplestwayofproducingaforecast.Thepersistencemethodassumesthattheconditionsatthetimeoftheforecastwillnotchange.Forexample,ifitissunnyand87degreestoday,thepersistencemethodpredictsthatitwillbesunnyand87degreestomorrow.Iftwoinchesofrainfelltoday,thepersistencemethodwouldpredicttwoinchesofrainfortomorrow.However,ifweatherconditionschangesignificantlyfromdaytoday,thepersistencemethodusuallybreaksdownandisnotthebestforecastingmethodtoThetrendsmethodinvolvesdeterminingthespeedanddirectionofmovementforfronts,highandlowpressurecenters,andareasofcloudsandprecipitation.Usingthisinformation,theforecastercanpredictwhereheorsheexpectsthosefeaturestobeatsomefuturetime.Forexample,ifastormsystemis1,000westofyourlocationandmovingtotheeastat250perday,usingthetrendsmethodyouwouldpredictittoarriveinyourareain4days.Thetrendsmethodworkswellwhensystemscontinuetomoveatthesamespeedthetrendsforecastwillprobablynotworkaswell.Theclimatologymethodisanothersimplewayofproducingaforecast.Thismethodinvolvesaveragingweatherstatisticsaccumulatedovermanyyearstomaketheforecast.Forexample,ifyouwereusingtheclimatologymethodtopredicttheweatherforNewYorkCityonJuly4th,youwouldgothroughalltheweatherdatathathasbeenrecordedforeveryJuly4thandtakeanaverage.Theclimatologymethodonlyworkswellwhentheweatherpatternissimilartothatexpectedforthechosentimeofyear.Ifthepatternisquiteunusualforthegiventimeofyear,theclimatologymethodwilloftenfail.Theogmethodisaslightlymorecomplicatedmethodofproducingaforecast.Itinvolvesexaminingtoday'sforecastscenarioandrememberingadayinthepastwhentheweatherscenariolookedverysimilar(anog).Theforecasterwouldpredictthattheweatherinthisforecastwillbehavethesameasitdidinthepast.Theogmethodisdifficulttousebecauseitisvirtuallyimpossibletofindapredictog.Variousweatherfeaturesrarelyalignthemselvesinthesamelocationsastheywereintheprevioustime.Evensmalldifferencesbetweenthecurrenttimeandtheogcanleadtoverydifferentresults.WhatofthefollowingfactorsisNOTmentionedinchoosingaforecastingNecessaryamountofDegreeofdifficultyinvolvedinCreativityoftheThepersistencemethodfailstoworkwellitisitisweatherconditionsstayweatherconditionschangeThetrendsmethodworkswellweatherfeaturesareconstantforalongperiodofweatherfeaturesaredefinedpredictionsonprecipitationarethespeedanddirectionofmovementareTheogmethodshouldnotbeusedinmakingaweatherforecasttheoglooksthecurrentweatherscenarioisdifferentfromthetheogismorethan10yearsthecurrentweatherscenarioisexactlythesameastheHistoricalweatherdataarenecessarythepersistencemethodandthetrendsthetrendsmethodandtheclimatologytheclimatologymethodandtheogThepersistencemethodandtheogObservethecriticismsofnearlyanymajorpubliceducationsystemintheworld,andafewofthemanycomintsaremoreorlessuniversal.Technologymovesfasterthantheeducationsystem.Teachersmustteachatthepaceofthesloweststudentratherthanthefastest.And—particularlyintheUnitedStates—schoolchildrenasagroupdon’tcaremuchfor,orexcelat,mathematics.Soit’shearteningtolearnthatanewkindof“classroomofthefuture”showspromiseatmitigatingsomeoftheseproblems,startingwiththatfundamentalpieceofclassroomfurniture:thedesk.AUKstudyinvolvingroughly400students,mostlyaged8-10years,andanewgenerationofmulti-touch,multi-user,computerizeddesktopsurfacesisshowingthatoverthelastthreeyearsthetechnologyhasappreciablyboostedstudents’mathskillscomparedtopeerslearningthesamematerialviatheconventionalpaper-and-pencilmethod.How?Throughcollaboration,mostly,aswellasbygivingteachersbettertoolsbywhichtomicromanageindividualstudentswhoneedsomeextrainstructionwhileallowingtherestoftheclasstocontinuemovingforward.Traditionalinstructionstillshowsrespectableefficacy(效力)atincreasingstudentsfluencyinmathematics,essentiallythroughmemorizationandpractice—dull,repetitivepractice.Buttheresearchershaveconcludedthatthesenewtouchscreendesksboostbothfluencyandflexibility—thecriticalthinkingskillsthatallowstudentstosolvecomplexproblemsnotsimplythroughknowingformulasanddevices,butbybeingabletofigureoutwhattherealproblemisandthemosteffectivemeansofstripitdownandsolvingOnereasonforthis,theresearcherssay,isthemulti-touchaspectofthetechnology.Studentsworkinginthenext-genclassroomcanworktogetheratthesametabletop,eachofthemcontributingandengagingwiththeproblemaspartofagroup.KnownasSynergyNet,thesoftwareusescomputervisionsystemsthatseeintheinfrared(红外的)spectrumtodistinguishbetweendifferenttouchesondifferentpartsofthesurface,allowingstudentstoaccessandusetoolsonthescreen,moveobjectsandvisualaidsaroundontheirdesktops,andotherwisephysicallyin ctwiththenumbersandinformationontheirscreens.Byusingthesescreenscollaboratively,theresearcherssay,thestudentsaretosomeextentteachingthemselvesasthosewithastrongergraspondifficultconceptspullotherstudentsforwardalongwiththem.WhichofthefollowingstatementsisNOTtrueofthepubliceducationItdoesnotcatchupwiththedevelopmentofTeacherspaymoreattentiontofastlearnersthanslowSomesimilarcomintsaboutitareheardindifferentManystudentsarenotgoodatlearningWhathasbeenfoundafterthenewtechisTeachersareabletogiveindividualizedattentiontostudentsin elessactiveinlearningStudentsshowpreferencetotheconventionalpaper-and-pencilThegapbetweenslowlearnersandfastlearnersgetmoreWhatisthebenefitstudentsgetfromthenewItmakesthemmorefluentinpublicItoffersthemmoreflexibilityinchoosingItiseffectiveinhelthemsolvephysicalItenablesthemtodevelopcriticalthinkingWhathappenswhenstudentsareusingthedesktopofthenewEverystudenthasanindividualStudentsusedifferenttoolsto ctwitheachThemulti-touchfunctionstimulatesThesoftwareinstalledautomaticallyidentifiesdifferentIthelpsfastlearnerstolearnItmakesteachers’instructionItenablesthemtoworkItallowsthewholeclasstolearnatthesameOntheTrailoftheHoneyOnarecentfieldtriptotheKalahariDesert,ateamofresearcherslearntalotmoreabouthoneybadgers(獾).Theteamemployedalocalwildlifeexpert,KitsoKhama,tohelpthemlocateandfollowbadgersacrossthedesert.Theirmainaimwastostudythebadgersmovementsandbehaviourasdiscreetly(谨慎地)aspossible,withoutfrighteningthemawayorcausingthemtochangetheirnaturalTheyalsonnedtotrapafewandstudythemcloseupbeforereleasingthem.Inviewoftheanimal’sreputation,thiswassomethingthatevenKhamawasreluctanttodo.“Theproblemwithhoneybadgersistheyarenaturallycuriousanimals,especiallywhentheyseesomethingnew,”hesays.“that,combinedwiththeirunpredictablenature,canbeadangerousmixture.Iftheysenseyouhavefood,forexample,theywon’tbeshyaboutcomingrightuptoyouforsomethingtoeat.They’reactuallyquitesociablecreaturesaroundhumans,butassoonastheyfeeltheymightbeindanger,theycan eextremelyvicious(凶恶的).Fortunaythisisrare,butitdoeshappen.”Theresearchconfirmedmanythingsthatwerealreadyknown.Asexpected,honeybadgersatecreaturestheycouldcatchandkill.Evenpoisonoussnakes,fearedandavoidedbymostotheranimals,werenotsafefromthem.Theresearchersweresurprised,however,bytheanimal’sfondnessforlocalmelons,probablybecauseoftheirhighwatercontent.Previouslyresearchersthoughtthattheanimalgotallofitsliquidrequirementsfromitsprey(猎物).Theteamalsolearntthat,contrarytopreviousresearchfindings,thebadgersoccasionallyformedloosefamilygroups.Theywerealsoabletoconfirmcertainresultsfrompreviousresearch,includingthefatthatfemalebadgersneversocializedwitheachother.Followingsomeofthemalebadgerswasachalleng,sincetheycancoverlargedistancesinashortspaceoftime.Somehuntingterritoriescovermorethan500squarekilometers.Althoughtheyseemhappytosharetheseterritorieswithothermales,thereareoccasionalfightsoveranimportantfoodsource,andmalebadgerscanbeasaggressivetowardseachotherastheyaretowardsotherspecies.Asthebadgersbecameaccustomedtothepresenceofpeople,itgavetheteamthechancetogetupclosetothemwithoutbeingthesubjectoftheanimal’scuriosity—ortheirsuddenaggression.Thebadgers’eatingpatterns,whichhadbeendisrupted,returnedtonormal.Italsoallowedtheteamtoobservemorecloselysomeoftheothercreaturesthatformworkingassociationswiththehoneybadger,astheseseemstoadoptthebadgers’relaxedattitudewhennearhumans.WhydidthewildlifeexpertsvisittheKalahariTofindwherehoneybadgersToobservehowhoneybadgersTocatchsomehoneybadgersforTofindoutwhyhoneybadgershaveabadWhatdoesKitsoKhamasayabouthoneyTheyshowinterestinthingstheyarenotfamiliarTheydonotenjoyhumanItiscommonforthemtoattackWhatdidtheteamfindoutabouthoneyThereweresomecreaturestheydidnotTheywereafraidofpoisonousTheymaygetsomeofthewatertheyneededfromFemalebadgersdidnotmixwithmaleWhichofthefollowingisatypicalfeatureofmaleTheydon’trunveryTheyhuntoveraverylargeTheydefendtheirterritoryfromotherTheyaremoreaggressivethanWhathappenedwhenhoneybadgersgotusedtohumansaroundTheybecamelessaggressivetowardsotherTheystartedeatingOtheranimalsstartedworkingwithTheylostinterestin下面的短文有5处空白，短文后有6个句子，其中5个取自短文，请根据短文内容将其分别放回原ToadsareArthriticandinArthritisisanillnessthatcancausepainandswellinginyourbones.Toads,abigprobleminthenorthofAustralia,aresufferingfrompainfularthritisintheirlegsandbackbone,anewstudyhasshown.Thetoadsthatjumpthefastestaremorelikelytobelargerandtohavelongerlegs.46.Thelargeyellowtoads,nativetoSouthandCentralAmerica,wereintroducedintothenorth-easternAustralianstateofQueenslandin193Sinanattempttostopbeetlesandotherinsectsfromdestroyingsugarcanecrops.Nowupto200millionofthepoisonoustoadsexistinthecountry,andtheyarerapidlyspreadingthroughthestateofNorthernTerritoryatarateofupto60kmayear.Thetoadscannowbefoundacrossmorethanonemillionsquarekilometers.47. AVenezuelanpoisonwastriedinthe1990sbuthadtobeabandonedafteritwasfoundtoalsokillnativefrogspecies.ThetoadshaveseverelyaffectedecosystemsinAustralia.Animals,andsometimespets,thateatthetoadsdieimmediayfromtheirpoison,andthetoadsthemselveseatanythingtheycanfitinsidetheirmouth.Aco-authorofthenewstudy,RickShine,aprofessorattheUniversityofSydney,saysthatlittleattentionhasbeengiventotheproblemsthattoadsfaceRickandhiscolleaguesstudiednearly500toadsfromQueenslandandtheNorthernTerritoryandfoundthatthoseinthelatterstatewereverydifferent.Theywereactive,sprintingdownroadsandbreedingquicklyAccordingtotheresultsofthestudy,thefastesttoadstravelnearlyonekilometrea Butspeedandstrengthcomeataprice—arthritisofthelegsandbackboneduetoconstantpressurecedonthem.Inlaboratorytests,theresearchersfoundthatafterabout15minutesofhop,arthritictoadswouldtravellessdistancewitheachhop.50. Thesetoadsaresoprogrammedtomove,apparently,thatevenwheninpainthetoadstravelledasfastandasfarasthehealthyones,continuingtheirrelentlessmarchacrossthelandscape.Toadsarenotbuilttoberoadrunners—theyarebuilttositaroundpondsandwetThetasknowfacingthecountryishowtoremovetheFurthermore,theysoontakeoverthenaturalhabitatsofAustralia’snativeToadswithlongerlegsmovefasterandtravellongerdistances,whiletheothersarebeingleftButthisadvantagealsohasabigdrawback—upto10%ofthebiggesttoadssufferfromButarthritisdidn’tslowdowntoadsoutsidethelaboratory,theresearchersBetterSolarEnergySystems:MoreHeat,MoreSolarphotovoltaicthermalenergysystems,orPVTs,generatebothheatandelectricity,but(51)nowtheyhaven’tbeenverygoodattheheat-generatingpartcomparedtoastand-alonesolarthermalcollector.That’sbecausetheyoperateatlowtemperaturestocoolcrystallinesiliconsolarcells,(52)letsthesilicongeneratemoreelectricitybutisn’taveryefficientwaytogatherheat.That’saproblemofeconomics.Goodsolarhot-watersystemscanharvestmuchmoreenergythanasolar-electricsystematasubstantiallylower(53).Andit’salsoaspaceproblem:photovoltaiccellscan(54)upallthespaceontheroof,leavinglittleroomforthermalInapairofstudies,JoshuaPearce,anassociateprofessorofmaterialsscienceandengineering,hasdeviseda(55)intheformofabetterPVTmadewithadifferentkindofsilicon.HisresearchcollaboratorsareKunalGirotrafromThinSiliconinCaliforniaandMichaelPathakandStephenHarrisonfromQueen’sUniversity,Canada.Mostsolarpanelsaremadewithcrystallinesilicon,butyoucanalsomakesolarcellsoutofamorphoussilicon,commonlyknown(56)thin-filmsilicon.Theydontcreateasmuchelectricity,buttheyarelighter,flexible,andcheaper.And,becausethey(57)muchlesssilicon,theyhaveagreenerfootprint.(58),thin-filmsiliconsolarcellsarevulnerabletosomebad-newsphysicsintheformoftheStaebler-Wronskieffect.“Thatmeansthattheirefficiencydropswhenyou(59)themtolight—prettymuchtheworstpossibleeffectforasolarcell,”Pearceexins,whichisoneofthe (60)thin-filmsolarpanelsmakeuponlyasmallfractionofthemarket.However,Pearceandhisteamfounda (61)toengineeraroundtheStaebler-Wronskieffectbyincorporatingthin-filmsiliconinanew (62)ofPVT.Youdon’thavetocooldownthin-filmsilicontomakeitwork.Infact,Pearce’sgroupdiscoveredthatbyheatingittosolar-thermaloperatingtemperatures,neartheboiling (63)ofwater,theycouldmakethickercellsthatlargely (64)theStaebler-Wronskieffect.Whentheyappliedthethin-filmsilicondirectlytoasolarthermalenergycollector,theyalsofoundthatbybakingthecellonceaday,they (65)thesolarcell’selectricalefficiencybyover10percent.51.A.B.C.D.52.A.B.C.D.53.A.B.C.D.54.A.B.C.D.55.A. B. C. D.56.A. B. C. D.57.A. B. C. D. B. C. D. 59.A. B. C. D.60.A. B. C. D.61.A. B. C. D.62.A. B. C. D.63.A. B. C. D.64.A.65.A.

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D.D.1 eA:216-22323-26 27-30431-35 36-40 41-45546-50651-55 56-60 61652013年英语TherewassomethingpeculiarinthewayhesA. B. C. D.IhavelittleinformationasregardsherfitnessfortheA. B. C. D.ShecameacrossthreechildrensleeunderaA.foundby B.passed C.tookanotice D.wokeTherulesaretoorigidtoallowforhumaneA. B. C. D.ItseemsincrediblethathehadbeenthereaweekA. B. C. D.ShegetsaggressivewhensheisA. B. C. D.RumorsbegantocirculateabouthisfinancialA. B. C. D.Asapolitician,heknowshowtomanipulatepublicA. B. C. D.TheseanimalsmigratesouthannuallyinsearchofA. B. C. D.HewastemptedbythehighsalaryofferedbytheA. B. C. D.ThewillneedtokeepawaryeyeonthisareaofA. B. C. D.MakesurethetableissecurelyA. B. C. D.Comeout,orI’llbustthedoorA. B. C. D.ThecontractbetweenthetwocompanieswillexpireA. B. C. D.Hepaused,waitingforhertodigesttheA. B. C. D.WideWorldofEngineerswhobuildandprogramrobotshavefascinatingjobs.Theseresearcherstinker(修补)withmachinesinthelabandwritecomputersoftwaretocontrolthesedevices."They'rethebesttoysoutthere,"saysHowieChosetatCarnegieMellonUniversityinPittsburgh.Chosetisarobotics,a whodesigns,buildsorprogramsrobots.WhenChosetwasakid,hewasinterestedinanythingthatmoved—cars,trains,animals.HeputmotorsonTinkertoycarstomakethemmove.Later,inhighschool,hebuiltrobotssimilartosmallcars.Hotocontinueworkingonrobots,hestudiedcomputerscienceincollege.ButwhenhegottograduateschoolattheCaliforniaInstituteofTechnologyinPasadena,Choset'slabmateswereworkingonsomethingevencoolerthanremoycontrolledcars:roboticsnakes.Somerobotscanmoveonlyforward,backward,leftandright.Butsnakescantwist()inmanydirectionsandtraveloveralotofdifferenttypesofterrain(地形)."Snakesarefarmoreinterestingthanthecars,"Chosetconcluded.AfterhestartedworkingatCarnegieMellon,Chosetandhiscolleaguestherebegandevelotheirownsnakerobots.Choset'steamprogrammedrobotstoperformthesamemovementsasrealsnakes,suchasslidingandinchingforward.Therobotsalsomovedinwaysthatsnakesusuallydon't,suchasrolling.Choset'ssnakerobotscouldcrawl(爬行)throughthegrass,swiminapondandevenclimbaflagpole.ButChosetwonderedifhissnakesmightbeusefulformedicineaswell.Forsomeheartsurgeries,doctorhastoopenapatient'schest,cuttingthroughthebreastbone.Recoveringfromthesesurgeriescanbeverypainful.Whatifthedoctorcouldperformtheoperationbyinsteadmakingasmallholeinthebodyandsendinginathinroboticsnake?ChosetteamedupwithMarcoZenati,aheartsurgeonnowatHarvardMedicalSchool,toinvestigatetheidea.Zenatipracticedusingtherobotonasticmodelofthechestandthentestedtherobotinpigs. calledMedroboticsinBostonisnowadaptingthetechnologyforsurgeriesonEvenafter15yearsofworkingwithhisteam'screations,"Istilldon'tgetboredofwatchingthemotionofmyrobots,"Chosetsays.Chosetbegantobuildrobotsinhigh B. C.NotSnakerobotscouldmoveinonlyfour B. C.NotChosetdidn'tbegindevelohisownsnakerobotsuntilhestartedworkingatCarnegie B. C.NotChoset'ssnakerobotscouldmakemoremovementsthantheonesothers B. C.NotTheapplicationofathinroboticsnakemakesheartsurgerieslesstime- B. C.NotZenatitestedtherobotonpeopleafterusingitin B. C.NotTherobotictechnologyforsurgeriesonpeoplehasbroughtahandsomeprofitto B. C.NotBlackBlackholescanbebestdescribedasasortofvacuum,suckingupeverythinginspace.Scientistshavediscoveredthatblackholescomefromanexplosionofhugestars.Starsthatareneardeathcannolongerburnduetolossoffuel,andbecauseitstemperaturecannolongercontrolthegravitational(重力的),hydrogenendsupputtingpressureontothestar’ssurfaceuntilitsuddenlyexplodesthenBlackholescomefromstarsthataremadeofhydrogen,othergasesandafewmetals.Whentheseexplodeitcanturnintoaslar-mass(恒星质量)blackhole,whichcanonlyoccurifthestarislargeenough(shouldbebiggerthanthesun)fortheexplosiontobreakitintopieces,andthegravitystartstocompacteverypieceintothetiniestparticle.Trytoseeandcompare:ifastarthat’stentimesthesizeofthesunendsupbeingablackholethat’snolongerthan70kilometers,thentheEarthwould eablackholethat’sonlyafractionofaninch!Objectsthatgetsuckedinablackholewillalwaysremainthere,nevertobreak.Butrememberthatblackholescanonlygobbleup(吞噬)objectswithinaspecificdistancetoit.It’spossibleforalargestarnearthesunto eablackhole,butthesunwillcontinuetostayince.Orbitsdonotchangebecausethenewlyformedblackholecontainsexactlythesameamountofmassaswhenitwasastar,onlythistimeitsmassistotallycontractedthatitcanendupasnobiggerthanastate.Sofar,astronomershavefiguredoutthatblackholesexistbecauseofAlbertEinstein’stheoryofrelativity.Intheend,throughnumerousstudies,theyhavediscoveredthatblackholestrulyexist.Sinceblackholestraplightanddonotgiveofflight,itisnearlyimpossibletodetectblackholesviaaescope.Butastronomerscontinuetostudygalaxiesspaceandthesolarsystemtounderstandhowblackholesmightevolve.Itispossiblethatblackholescanexistformillionsofyears,andlatercontributetoabiggerprocessingalaxies,whichcaneventuallyleadtocreationofnewentities.Scientistsalsocreditblackholesashelpfulinlearninghowgalaxiesbegantoform.IsthereIsthereproofthatblackholesreallyWhataredifferenttypesofblackHowareblackholesHowwereblackholesWhathappenstotheobjectsaroundablackWhatareblackholesmadeParagraphParagraphParagraphBlackholesareformed Whenalargestarexplodes,thegravitycompactseverypiece Anewlyformedblackholeandthestaritcomesfromare AlbertEinstein’stheoryofrelativityhelpsto thecreationthecreationofnewanexplosionofhugethetiniestthesameamountoftheexistenceofblackafractionofanTheUnited