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下面是一篇杂志文章,请将标有A&G的段落插入文章中标号1-5的合适位置,使这篇文章意义完整,结构连贯;其中有一个段落是多余的。
CATV is a short way of saying “community antenna（社区天线）television”. But “cable television” is the term most people use. [16] __________
Television signals do not follow the curve（曲线）of the earth.[17] __________ If you live only a few miles from a station, you may not get any picture at all.
[18] __________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 charge.
CATV worked well, and soon new uses were found for it. Local stations could feed programs into empty channels that were not in use. [19] __________
Today, cable television has moved into cities. It brings in extra programs that city viewers with regular antennas cannot see. [20] __________
A. They travel in straight lines in all directions. Signals from a TV station move toward the horizon（地平线）and then go into space.
B. The wide use of CATV is due to the widespread of the TV set in almost every family.
C. Cable television allows viewers to receive TV programs that they cannot pick up with their regular antennas.
D. People along the cable could have local news, weather reports, and farm and school news at no extra charge.
E.CATV began in 1948.People in places far from TV stations shared the cost of putting up high antennas.
F. It is also used in many classrooms throughout the country.
G. Therefore, they could watch TV with extra charge.