Television-----the most pervasive and persuasive of modern technologies, marked by rapid change and growth-is moving into a new era, an era of extraordinary sophistication and versatility, which promises to reshape our lives and our world. It is an electronic revolution of sorts, made possible by the marriage of television and computer technologies.
The word television, derived from its Greek and Latin roots, can literally be interpreted as sight from a distance. Very simply put, it works in this way: through a sophisticated system of electronics, television provides the capability of converting an image into electronic impulses, which can be sent through a wire or cable. These impulses, when fed into a receiver , can then be electronically reconstituted into that same image.
Television is more than just an electronic system, however. It is a means of expression, as well as a vehicle for communication, and as such becomes a powerful tool for reaching other human beings.
The field of television can be divided into two categories determined by its means of transmission. First, there is broadcast television, which reaches the masses through broad-based airwave transmission of television signals. Second, there is nonbroadcast television, which provides for the needs of individuals or specific interest groups through controlled transmission techniques.
Traditionally, television has been a medium of the masses. We are most familiar with broadcast television because it has been with us for about thirty-seven years in a form similar to what exists today. During those years, it has been controlled, for the most part, by the broadcast networks, ABC, NBC, and CBS, who have been the major purveyors of news, information, and entertainment. These giants of broadcasting have actually shaped not only television but our perception of it as well. We have come to look upon the picture tube as a source of entertainment, placing our role in this dynamic medium as the passive viewer.
冀教版英语四下(三起)《Unit 2 Lesson13 How’s the Weather Today》PPT课件1[www.edudown.net]
冀教版英语四下(三起)《Unit 2 Lesson13 How’s the Weather Today》PPT课件[www.edudown.net]
冀教版英语四下《Unit 1 Lesson4 Where is it》PPT课件1[www.edudown.net]
冀教版英语四下《Unit 3 Lesson18 Are you short or tall》flash课件2
冀教版英语四下《Unit 1 Lesson3 what’s this》flash课件
冀教版英语四下《Unit 2 Lesson13 How’s the weather today》flash课件
冀教版英语四下(三起)《Unit 3 Lesson19 What are you wearing》PPT课件[www.edudown.net]
冀教版英语四下《Unit 2 Lesson14 What time is it》flash课件包
冀教版四年级下Unit 3《lesson 20 where do you live》flash课件
冀教版英语四下《Unit 2 Lesson12 rain and sun》flash课件
冀教版英语四下《Unit 2 Lesson11 When Is It》PPT课件1[www.edudown.net]
冀教版英语四下《Unit 2 Lesson11 When Is It》PPT课件[www.edudown.net]
冀教版英语四下《Aa Ee Ii Oo Uu 音标学习》PPT课件[www.edudown.net]
冀教版英语四下《Unit 1 Lesson3 Is this your pencil》PPT课件[www.edudown.net]
冀教版四年级下Unit 3《lesson 22 do you walk to school》ppt课件
冀教版英语四下《Unit 2 Lesson15 Are you ready for a quiz》flash课件
冀教版英语四下《Unit 3 Lesson17 How old are you》flash课件2
冀教版英语四下《Unit 1 Lesson3 Is this your pencil》PPT课件1[www.edudown.net]
冀教版英语四下《Unit 1 Lesson4 where is it》flash课件
冀教版英语四下《Unit 3 Lesson18 Are you short or tall》flash课件
冀教版英语四下《Unit 1 Lesson2 Boy and girl》flash课件
冀教版英语四下《Lesson7 Are you ready for a quiz》PPT课件[www.edudown.net]
冀教版英语四下《Unit 1 Lesson1 How Are You》PPT课件包
冀教版英语四下《Unit 2 Lesson16 练习》flash课件
冀教版英语四下《Unit 3 Lesson17 How old are you》PPT课件包
冀教版英语四下《Unit 2 Lesson13 How’s the Weather Today》flash课件包1
冀教版英语四下《Lesson25 My Favourite Colours》PPT课件[www.edudown.net]
冀教版英语四下《Unit 1 Lesson2 A new friend》flash课件
冀教版英语四下《Unit 2 Lesson9 Months of the year》flash课件
冀教版四年级下Unit 3《lesson 22 do you walk to school》flash课件之一