任务型阅读：Isitpossibleto“catch”light---andthenletitgo？ScientistsfromHarvardUniversityrecentlydemonstratedawaytocatchandreleaselight---butit’snoteasy.LeneHauisthephysicistwholedthisstudyofhowtostopandleaselight.Physicistsstudymatter,energyandmotion.InthecaseofHau’sexperiment,shehadtouseherknowledgeofallthree.Thelighttrapwasn’tbuiltfromnormalmaterials.HauandherteaminsteadusedakindofmaterialcalledaBose-Einsteincondensate,orBEC.Thismaterialisunusualbecauseitdoesnotrepresentanyofmatter’susualstates:solid,liquidorgas.It’snotevenaplasma(等离子),thefourthstateofmatterfoundinhigh-energyexperiments.Instead,BECsareafifthstateofmatter.Theyexistonlyatcoldestpossibletempe-ratures,afractionofadegreeaboveabsolutezero.Whensomematerialsarecooledtoalmostabsolutezero,theiratomsseemtocollapseintooneteeny-tinyblob,andthatblobiscalledaBEC.ThescientistsusedaBECtostoplightinawaysimilartothegameofGossip.It’saneasygametoplay:Onepersonwhispersamessagetoasecondperson,wholistens.Thatpersonthenturnstoathirdpersonandpassesonthemessage.Thethirdpersonshouldnowhavethesamemessageastheonesentbythefirstperson.InHau’sexperiment,thelightislikethemessage,andtheBECislikethepersoninthemiddle---whohearsthemessageandthenpassesiton.HauandherteamfiredapulseoflightintoaBECandthelightchangedasmallgroupofatoms.ThesechangedatomsdugalittleholeforthemselvesintheBEC---likeafootprint.Theresearchteamthenturnedoffacontrollaser,whichmadethelight’sfootprint“sit”intheBEC.“Itcansnuglysitthereforlongperiodsoftime,”HautoldScienceNews.Thescientistswaitedfor1.5secondsandthenturnedthecontrollaserbackon.Whentheydid,thetrappedlightpulsecameoutoftheBEC.___1____tocatchandreleaselightThefactaboutlightPeoplehave____2____infindingawaytocatchlightandletitgo.Arecentstudy____3_____ScientistsfromHarvardUniversity____4____Thelighttrapwasbuilt____5____afifthstateofmattercalledBECs____6____ofanyofmatter’susualstates.____7_____★ScientistsfiredapulseoflightintoaBEC,which___8____tochangedatoms.★Thechangedatomsthen“sat”intheBEClikeafootprintforlongperiodsoftimewhenacontrollaserwaswithdrawn.★Afterseveralseconds,thecontrollaserwas___9_____onagainandthetrappedlightpulsewasreleasedoutoftheBEC.ConclusionTheexperimentmakesitcome___10_____tocatchandreleaselight.Answers:1.How2.Difficulty/trouble3.Conductors/researchers4.Material5.using6.Instead7.Process8.Contributed/led9.turned10.true来源：《学生双语报》2010-2011学年度第41期（杨红）
