TV Goes Digital Coming soon to your TV: views of the hottest live basketball plays from any seat in the stadium. What a bette

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问题                                               TV Goes Digital
   Coming soon to your TV: views of the hottest live basketball plays from any seat in the stadium. What a better look at that three-point shot? Call for a replay from behind the basket. Or better yet, follow the "view" of the ball as it goes through the net.
   While watching, you might use a built-in speakerphone to talk with a fan in the stands. Or send the score via e-mail to your father in Japan. Sounds impossible? It won’t be when the computerized television industries combine to create digital TV-machines that receive, send, store, and manipulate TV programs the way computers now manipulate other data.
   Industry and government representatives recently reached an agreement on how this technology will take place. New digital TVs that allow current TVs to receive digital signals may hit stores by next spring.
   To understand how the digital revolution will change the way you watch TV it helps to know how TVs work now. Today, TV networks such as CBS and Fox broadcast TV shows as analogue electrical signals. These signals travel via the airwaves, satellites, or cable as a continuous stream of electromagnetic energy(like light and radio waves). But this system leaves a lot of room for error. The main problem is that interference can change the voltage of the signal as it travels. This may result in a distorted or miscolored picture. If we send out the signal in a form that is nearly free from interference-binary(两位数的)code, pictures and colors are not distorted.
   You’ll need to buy a new TV to receive these signals. And the new sets may cost 1,000 US dollars more than today’s TVs. But they’ll come with other benefits that may make the price worthwhile. For one thing, the screens will be wider, like movie screens. In addition, the color will be richer. And you’ll also get digital CD-quality sound.
   Besides these benefits, digital TVs can offer you a much wider choice of programs. Digital data can expand TV choices because computers can compress digital signals. Broadcasters will be able to send six times as much information on the same "channel".

选项 A、interference-free pictures
B、a richer color
C、a wider screen
D、good reception of signals

答案D

解析
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