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职称英语历年真题《理工B》概括大意职称英语历年真题《理工B》概括大意精选2017年职称英语考试复习已经开始，为了促进大家的学习积极性，下面是yjbys网小编提供给大家关于职称英语历年真题《理工B》概括大意精选，希望对大家的备考有所帮助。BlackHoles(1)Blackholescanbebestdescribedasasortofvacuum,suckingupeverythinginspace.Scientistshavediscoveredthatblackholescomefromanexplosionofhugestars.Starsthatareneardeathcannolongerbumduetolossoffuel,andbecauseitstemperaturecannolongercontrolthegravitational(重力的)force,hydrogenendsupputtingpressureontothestar'ssurfaceuntilitsuddenlyexplodesthencollapses.(2)Blackholescomefromstarsthataremadeofhydrogen,othergasesandafewmetals.Whentheseexplodeitcanturnintoastellar-mass(恒星质量)blackhole,whichcanonlyoccurifthestarislargeenough(shouldbebiggerthanthesun)fortheexplosiontobreakitintopieces,andthegravitystartstocompacteverypieceintothetiniestparticle.Trytoseeandcompare:ifastarthat'stentimesthesizeofthesunendupbeingablackholethat'snolongerthan70kilometers,thentheEarthwouldbecomeblackholethat'sonlyafractionofaninch!(3)Objectsthatgetsuckedinablackholewillalwaysremainthere,nevertobreakfree.Butrememberthatblackholescanonlygobbleup(吞噬)objectswithinaspecificdistancetoit.It'spossibleforalargestarnearthesuntobecomeablackhole,butthesunwillcontinuetostayinplace.Orbits(轨道)donotchangebecausethenewlyformedblackholecontainsexactlythesameamountofmassaswhenitwasastar,onlythisitsmassistotallycontractedthatitcanendupasnobiggerthanastate.(4)Sofar,astronomershavefiguredoutthatblackholesexistbecauseofAlbertEinstein'stheoryofrelativity.Intheend,throughnumerousstudies,theyhavediscoveredthatblackholestrulyexist.Sinceblackholestraplightanddonotgiveofflight,itisnotpossibletodetectblackholesviaatelescope.Butastronomerscontinuetoexploregalaxies(银河系),spaceandthesolarsystemtounderstandhowblackholes.Itispossiblethatblackholescanexistformillionsofyears,andlatercontributefurtherprocessingalaxies,whichcaneventuallyleadtocreationofnewentities.Scientistsalsocreditblackholesashelpfulinlearninghowgalaxiesbegantoform.23"——26概括大意23.Paragraph1_______
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