高二英语精品同步课件：UNIT1教材背景链接（牛津译林版选修7）.ppt

1、Unit 1Living with technology教材背景链接名言佳句名言佳句Anything one man can imagine，other men can make real.Jules Verce，French writer但凡人能想像得到的事物，必定有人能将它实现。法国作家凡尔纳It has become appallingly obvious that our technology has exceeded our humanity.America Albert Einstein显而易见我们的人性已远远落后于我们的技术。美国阿尔伯特爱因斯坦有线电视从出现至今已经经历了半个多

2、世纪的发展。你知道它是怎样发展起来的吗？The development of cable TVThere used to be only four television networks in the United States.Because of the类文欣赏类文欣赏frequencies given to television，the signals could only be received in a line of sight from the antenna(天线)In 1948，people living in remote valleys in Pennsylvania s

3、olved their reception problems.They put antennae on hills，so they could run cables to theirhouses.These days the same technology is also used.Viewers all over the country can watch a wide variety of programs and channels.By the early 1990s，cable television had reached nearly half of the homes in the

4、 United States.The earliest cable systems were，in fact，strategically placed antennae with very long cables.However，the signal from the antenna became weaker and weaker as it traveled through the cables.In the end，cable providers had to insert amplifiers(放大器)so as to help strengthen the signal.Limita

5、tions in these amplifiers used to be a great issue for cable system designers.“In a cable system，the signal may have gone through 30 or 40 amplifiers before it reaches your house，one every 1,000 feet or so，”says Bill Wall，technical director for subscriber networks at ScientificAtlanta，“With each amp

6、lifier，you will get noise.Plus，if one of the amplifiers failed，you lost the picture.Cable got a reputation for not having the best quality of picture and for not being reliable.”In the late 1970s，cable television found a solution to the amplifier problem.By then，they had also developed technology th

7、at allowed them to add more programming to the service of cable systems.Today，U.S.cable systems deliver hundreds of channels to millions of homes.It also provides a growing number of people with highspeed Internet access.In addition，some cable systems even let you make telephone calls and receive ne

8、w programming technologies!Read the text and then tell the following sentences true(T)or false(F)1 In the 1950s，people in remote valleys in Pennsylvania had no access to TV programs.()F2Cable TV was once thought to be unreliable.()3In the past，the longer the signal traveled，the weaker it became.()TT