Unit 1  Will people have robots?

　　keys:
　　1. more    2.less    3. fewer    4. more    5. less    6. fewer 
　　iii、閱讀練習(xí)
catv
　　catv is a short way saying “community antenna (公用天線) television”. but “cable　television” is the name most people use. cable television allows viewers(觀眾) to receive tv  programs that they can not pick up with their ordinary antenna.
　　television signals (信號(hào)) do not follow the curve(曲線) of the earth. they travel in straight lines in all directions. signals from a tv station move towards the horizon(水平線) and then go into space. if you live only a few miles from a tv station, you may get a good picture on your set. but if you live more than 50 miles from a station, you may not get any pictures at all.
　　catv began in 1948. people in places far from tv stations had to pay for 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(當(dāng)?shù)氐? station. from the station, thick wires called cable ran out to nearby homes. each person using the cable paid a monthly charge(費(fèi)用).
　　catv worked well, and soon new uses were found for it. local stations could feed programs into empty channels that were not in use. people along the cable could have local news, weather report, and farm and school news at no extra charge.
　　today, cable television has moved into cities. it brings in extra programs that city viewers with ordinary antenna can not see. it is also used in many classrooms throughout the country.
　　根據(jù)短文內(nèi)容，選擇正確答案。
　　1. from the first paragraph we know that _____.
　　a. most people use cable television　
　　b. “community antenna” is used for cable television
　　c. a community antenna is used for cable television
　　d. an ordinary antenna can not pick up tv programs
　　2. of the following, which is not the way tv signals travel?
　　a. in a curve. 　　　　　　　　
　　b. in a straight line.
　　c. in all directions. 　　　　　　　
　　d. towards the horizon.
　　3. cable tv is becoming more and more popular because _____.
　　a. it is free of charge 　　　　　　
　　b. it provides all tv users good pictures
　　c. it only needs a bit of cable　　　　
　　d. it can provide more programs
　　4. on the whole, this passage is about ______.
　　a. how to put up high antennas　　　　
　　b. a way of picking up better tv programs
　　c. how to use the empty channels on your tv set