Unit1Livingwithtechnology-Section1Section2BackgroundinformationI.Electricity电Themodernageisanageofelectricity.Peoplearesousedtoelectriclights,radio,televisions,andtelephonesthatitishardtoimaginewhatlifewouldbelikewithoutthem.Whenthereisapowerfailure,peoplegrope(摸索)aboutinflickering(摇曳的)candlelight,carshesitateinthestreetsbecausetherearenotrafficlightstoguidethem,andfoodspoilsinsilentrefrigerators.Yet,peoplebegantounderstandhowelectricityworksonlyalittlemorethantwocenturiesago.Naturehasapparently(显然地)beenexperimentinginthisfieldformillionsofyears.Scientistsarediscoveringmoreandmorethatthelivingworldmayholdmanyinterestingsecretsofelectricitythatcouldbenefithumanity.Alllivingcellsendouttinypulsesofelectricity.Astheheartbeats,itsendsoutpulsesofrecord;theyformanelectrocardiogram(心电图),whichadoctorcanstudytodeterminehowwelltheheartisworking.Thebrain,too,sendsoutbrainwavesofelectricity,whichcanberecordedinanelectroencephalogram.Theelectriccurrentsgeneratedbymostlivingcellsareextremelysmall–oftensosmallthatsensitiveinstrumentsareneededtorecordthem.Butinsomeanimals,certainmusclecellshavebecomesospecializedaselectricalgeneratorsthattheydonotworkasmusclecellsatall.Whenlargenumbersofthesecellsarelinkedtogether,theeffectscanbeastonishing.Theelectriceel(鳗鲡)isanamazingstoragebattery.Itcanseedajoltofasmuchaseighthundredvoltsofelectricitythroughthewaterinwhichitlive.(Anelectrichousecurrentisonlyonehundredtwentyvolts.)Asmanyasfour-fifthsofallthecellsintheelectriceel’sbodyarespecializedforgeneratingelectricity,andthestrengthoftheshockitcandelivercorrespondsroughlytolengthofitsbody.II．MovieMusic有声电影Accustomedthoughwearetospeakingofthefilmsmadebefore1927as“silent”,thefilmhasneverbeen,inthefullsenseoftheword,silent.Fromtheverybeginning,musicwasregardedasanindispensable(不可缺少的)accompaniment;whentheLumierefilmswereshownatthefirstpublicfilmexhibitionintheUnitedStatesinFebruary1896,theywereaccompaniedbypianoimprovisations(即席创作)onpopulartunes.Asmovietheatersgrewinnumberandimportance,aviolinist,andperhapsacellist,wouldbeaddedtothepianistincertaincases,andinthelargermovietheaterssmallorchestras(管弦乐队)wereformed.Foranumberofyearstheselectionofmusicforeachfilmprogramrestedentirelyinthehandsoftheconductororleaderoftheorchestra,andveryoftentheprincipalqualificationforholdingsuchapositionwasnotskillortastesomuchastheownershipofalargepersonallibraryofmusicalpieces.themusicalarrangementwasnormallyimprovised(临时准备)inthegreatesthurry.Tohelpmeetthisdifficulty,filmdistributingcompaniesstartedthepracticeofpublishingsuggestionsformusicalaccompaniments.In1909,forexample,theEdison用心爱心专心116号编辑Companybeganissuingwiththeirfilmssuchindicationsofmoodas“pleasant”,“sad”,“lively”.Thesuggestionsbecamemoreexplicit,andsoemergedthemusicalcuesheetcontainingindicationsofmood,thetitlesofsuitablepiecesofmusic,andprecise(精确的)directionstoshowwhereonepieceledintothenext.Certainfilmshadmusicespeciallycomposedforthem.ThemostfamousoftheseearlyspecialscoreswasthatcomposedandarrangedforD.WGriffith’sfilmBirthofaNation,whichwasreleasedin1915.Note:美国通俗音乐分类：1．Jazz;1)traditionaljazz----a)blues,代表人物：BillyHoliday2)modernjazz------a)cooljazz(=progressivejazz)高雅爵士乐。Eg.KennyG.2.gospelmusic福音音乐，主要源于Nerospirituals.Eg.DollyParker,MahaliaJackson3.CountryandWesternmus...
