net changes life2

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1、Unit3NetChangesLife(II)TrainingFocus---Recognizingtimeandevents---Selectingfacts---Makingjudgments---IdentifyingmajorpointsListeningSkillsBackgroundInformationLanguageStudyAdditionalMaterialContents:PartIWarmingupPartIINetchangesdormlifePartIIIGlobalmultiagi

2、antPartIWarmingupKeyWords:telegraphawirecableradioprogramdirecttelephonecallscommunicationssatellitenetworksVocabulary:orbitPennsylvaniaA.Abriefhistoryofcommunications.1.ThefirstusefultelegraphsweredevelopedinBritainandtheUnitedStatesinthe1830s.Eachletteroft

3、healphabetandeachnumberhadtobesentseparatelybyadevicecalledatelegraphkey.2.OnAug.5th,1858,thefirstmessagewastransmittedbyawirecableundertheAtlanticOcean.Thismeantthatinformationnowtookonlyamatterofhourstoreachmostlargecitiesintheworld.3.OnNov.2nd,1920,radios

4、tationKDKAinPittsburgh,Pennsylvaniabroadcastthefirstradioprogram.Withinafewshortyears,newsandinformationcouldbeheardanywherearadiobroadcastcouldreach.4.AfterWorldWarII,anewinventionappeared:television.Intheindustrialcountries,televisionquicklybecamecommoninm

5、osthomes.5.Inthe1950s,twoimportanteventstookplacethatgreatlyaffectedthecommunicationofinformation.ThefirstwasatelevisionbroadcastthatshowedtheeastcoastandthewestcoastoftheUnitedStatesatthesametime.PeoplecouldseetworeporterstalktoeachotheralthoughtheyWeresepa

6、ratedbyacontinent.6.TheothereventhappenedonSep.25th,1956.ThatwaswhenthefirsttelephonecableundertheAtlanticOceanmadeitpossibletomakedirecttelephonecallsfromtheUnitedStatestoEurope.7.InJuly1962,thefirstcommunicationssatellitewasplacedinorbitaroundtheearth.Thes

7、peedofinformationagaingreatlyincreased.8.Todayexpertssaythereareabout300millioncomputersconnectedtonetworksthatprovidelinkswithcomputersaroundtheworld.Keys:1-c2-e3-a4-d5-b6-g7-h8-fStructureAnalysis:1.ThefirstusefultelegraphsweredevelopedinBritainandsubjectth

8、eUnitedStatesinthe1830s.adverbial2.OnNov.2nd,1920,radiostationKDKAinPittsburgh,adverbialPennsylvaniabroadcastthefirstradioprogram.object3.Thefirstwasatelevisionbroadcast.predicativeB.Ashortpassa