CATV is a short way of saying “community antenna( 天线 ) television.” But “cable television” is the term most people use. Cable television allows 46 to receive TV programs that they cannot pick up with their 47 antennas. Television signals do not 48 the curve of the earth. They travel in straight lines in all directions. Signals from a TV station 49 toward the horizon and then go into space. If you live only a few miles 50 a station, you may not get any picture at all. CATV began in 1948. People in places far from TV stations shared the 51 of putting up high antennas. A community antenna was usually placed on a hill, a mountain, or on a high tower. The antenna picked up TV signals and fed them into a small local station. From the station, thick wires called cables ran out to nearby homes. Each person using the cable paid a monthly 52 . CATV worked well, and soon new uses were found 53 it. Local stations could feed programs into 54 channels that were not in use. People along the cable could have local news, weather reports, and farm and school news at no 55 charge. Today, cable television has moved into cities. It brings in extra programs that city viewers with regular antennas cannot see. It is also used in many classrooms throughout the country.