题目

阅读理解 Look at your modern TV, and you see nothing less than a technological miracle. Scientists began experimenting with the concept of television more than a century ago. But decades would pass before it was brought to the public at the 1939 World's Fair. More time passed before TV sets were in stores—and even then, it took a while until most people had one. During the 1950s, TVs were expensive, screens were small and the picture wasn't always clear. Moreover, early programs were in black and white; color wasn't in wide use until the mid-1960s. Viewers didn't have a lot of choice, either. Instead of hundreds of channels to choose from, most cities offered only three or four. Early TVs worked with the use of analog (模拟的) signals. Here's how they worked：Using a giant transmission tower, the local television station sent those waves through the air. Antennas on the roofs of buildings and homes received those waves and transported the signal to the television sets inside. By 2009，TV stations replaced analog signals with digital signals, which is the standard used today. Modern digital TV uses different information streams. For example, one stream is for the picture; another stream is for the audio. Pictures are created by basic units called pixels (像素). Your screen has tens of thousands of pixels. Basically, three colors—red, blue and green—form other colors in various combinations, and the picture is created from all the pixels together. Groups of bits are formed into larger units called bytes (字节)，which are the link between the content you're watching and your TV. Your digital smart TV has an interface that allows you to control all the functions. Basically, a smart TV is a computer, large monitor and receiver all in one package. In the future, there will be more functions equipped in your cellphone and TV and thus offer you more choices. Whether the TV will be a screen for your cellphone is up to you. （1） Which of the following was a new characteristic of the TV sets in the mid-1960s? A . The screens were small. B . The pictures were unclear. C . The pictures were colored. D . Many channels were offered. （2） What is mainly talked about in paragraph 3? A . The development of TVs. B . The working process of TVs. C . The problems viewers meet. D . The advantages of modern TVs. （3） What can we know about modern digital TVs from the text? A . They are always used as computers by viewers. B . Their pictures are more colorful with higher pixels. C . Users can control some of the functions on their computers. D . Bytes are in charge of linking the program to the TVs. （4） Where is the text most probably from? A . A science-tech magazine. B . A news report. C . A travel brochure. D . A storybook. 答案： C B B A

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