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Unit3Task1:¡¾´ð°¸¡¿A.1)voicesignals£¬videoimages£¬computerdata2)1983£¬fourmillion£¬game-playing£¬educational£¬financial£¬budgeting,£¬accounting3)1983£¬52percent£¬16percent4)18¡ª19£¬25percent£¬18percent£¬over-60s£¬3percent£¬87percentB.1)ISDNstandsfortheintegratedservicesdigitalnetwork.2)Somepeopleattributethisgrowthindustrytotherecessionwhichledtoredundanciesandashorterworkingweek,andthisinturnledtomoreleisuretime.Thenpeoplebeganindulginginhomeentertainmentintheirextrafreetime.Hundredsofcompanieshavesprunguptofillthisgap,andthesports,DIYandhomeentertainmentindustriesareachievingphenomenalsuccess.3)Havingteenagersinthehomewasadecisivefactorinthepurchaseofapersonalcomputer.4)Usersbecomemoreknowledgeableandwantmoreexpensivemachineswithallkindsofnewthings.5)Withmoretimeontheirhandspeopletendtospendmoretimekeepingfitwiththehelpofallkindsofnewgadgets.6)Rubik'scubeisafamoustoyoftheearly1980s,whichhassixsides,eachcomposedofninerotatingfaces,with43quintillioncombinations.7)Hackermeansanenthusiastwhobreaksintocomputers.Theyusetheirhomecomputerstobreakintosupposedlysecuregovernmentandbusinesscomputers,forexampleinbanks,labsandresearchcenters.¡¾ÔÎÄ¡¿JustbeforeIgiveafewdetailsaboutthefunaspectofcomputers¡ªthatis,foruseathomeandforentertainment¡ªI'dliketomentionacoupleoffactsabouttheoutlookforISDN¡ªthat'stheintegratedservicesdigitalnetwork¡ªanditforeseesaworld-widetelecommunicationsnetworkwhichcouldtransmittelexandvoicesignalsand,indeed,full-colorvideoimagesandhigh-speedcomputerdata.Now,canyoujustimaginehavingameetingwithyourcolleaguesaroundtheworldwithoutevenleavingyouroffice?Well,that'swhatworld-widevideoteleconferencingcando,andit'sonthecardsthatinternaltoll-freetelephonesmaybeavailableandalsofastercomputertransmissionwithadigitalnetwork.Andhowareallthesemarvelousthingsachieved?Well,therearesatelliterelays,anddigitalpacketswitching,andlaserdeviceswhichtransmitoverfiber-opticcables.Butmoreaboutthatanothertime.AndafterthatslightdiversionI'llgetbacktoatotallydifferentaspectofmoderntechnology¡ªhomecomputers,orPCs¡ªthatstandsforpersonalcomputers.First,abitofbackground.Somepeopleattributethisgrowthindustrytotherecessionwhichledtoredundanciesandashorterworkingweek,andthisinturnledtomoreleisuretime.Sowhatarepeopledoingwiththisextrafreetimethat'sontheirhands?They'reindulginginhomeentertainment,that'swhat!Hundredsofcompanieshavesprunguptofillthisgap,andthesports,DIYandhomeentertainmentindustriesareachievingphenomenalsuccess.In1983intheUS,therewerefourmillionPCs,andgame-playingwastheprincipaluse,witheducationaluseaclosesecond;andinthirdplacewasthefinancialfunctionforthingslikebudgeting,balancingchequebooks,accountingandforecastingandsoon.Toillustratethiswithafewconcretefigures,fromtheStatesagain,in1983,52percentofthesoftwarewasforentertainmentprograms,whereasonly16percentwaseducational.Possiblythiscouldbeexplainedbytheshortlifespanofcomputergames,andhavingteenagersinthehomewasadecisivefactorinthepurchaseofapersonalcomputer,ashouseholdswithchildreninthisage-rangewere50percentmorelikelytobuythem.Asfarastheinterestversusdisapprovalstatisticsgo,inthe18-19age-group,25percentexpressedinterestinPCsand18percentdisapproval;andattheotherendofthescale,theover-60sshowedonly3percentinterestandaresounding87percentdisapproval!AndthistrendtowardsPCsislikelytocontinueasusersbecomemoreknowledgeableandwantmoreexpensivemachineswithallkindsofnewthings.Andthere'sawiderangeinsizes,too,astheportablemarketexpands,andnowyoucanbuyafeatherweightlap-sizemodelthat'slessthan2kg,orsomethinglargerataround12kgbutstillportable.Justtodigressslightly,I'dliketopointoutthatmicrotechnologyhashitotheraspectsofthehomeandleisureindustryaswell.Withmoretimeonourhandsitseemswe'respendingmoretimekeepingfit,andfitnesshasbecomearealgrowthindustry,anditseemspronetogadgetryaswell!Thereareallsortsofnewthingsonthemarketthesedays.Take,forexample,thewatchesthatmonitoryourpulserateasyoujogordoaerobics,orexercisebicycleswithsensorsinthehandgripstocheckyourpulserateandthendisplayitonascreen.Andforthoseofyouwhorememberthatfamoustoyoftheearly80s¡ªRubik'scube,theonewithsixsides,eachcomposedofninerotatingfaces,with43quintillioncombinations¡ªwell,anyway,inalabintheUSthey'reworkingonaCubot¡ªthat'saself-containedrobotusingmicroprocessorsandmechanics¡ªtosolveit.ButI'mgettingoffthetrackagain,sobacktoourhomecomputerswithafinalwarning.Thetechnicalinnovationsofthelastcoupleofdecadeshaveledtoahostofnewwordsinourvocabulary,andoneoftheseishacker¡ªthat'sH-A-C-K-E-R¡ªanditsimplymeansanenthusiastwhobreaksintocomputers.And,notsolongagointheStates,teenagerswhowerehackersusedtheirhomecomputerstobreakintosupposedlysecuregovernmentandbusinesscomputers,forexampleinbanks,labsandresearchcenters.Theyjusttriedoutdifferentpasswordsuntiltheyfoundtherightone.Andasoneseventeen-year-oldsaid,'Itwaslikechild'splay.'Andallthat'sneededisahomecomputerandamodem¡ªthat'sM-O-D-E-M¡ªwhichisadevicethatallowscomputerstotransmitdataoverthephonelines¡ªand,ofcourse,abasicknowledgeofhowtooperateacomputer!Andthishasledtotangledlegalan