精选优质文档-倾情为你奉上Unit 4 Turn Off TV: A Quiet HourI. Background Information1. TV: Past and PresentA demonstration of television was held at the New York Worlds Fair in 1939, and during the 1940s networks were established and television sets began to be sold. But, for a while, radio still had complete control of the entertainment industry.In the early 1950s, the television started to take the place of radio in the United States. But television was only on in the evenings with few choic
