2. 外语
  3. The Television Camera The television camera is rather like the human eye. Both the eye and the camera have a lens, and both

The Television Camera The television camera is rather like the human eye. Both the eye and the camera have a lens, and both

admin2011-01-05  68
问题                         The Television Camera
    The television camera is rather like the human eye. Both the eye and the camera have a lens, and both produce a picture on a screen. In each case the picture is made up of millions of spots of light.
    Let us see how the eye works. When we look at an object-a person, a house, or whatever it may be, we do not see all the details of the object in one piece. We imagine that we do, but this is not the case. In fact, the eye builds up the picture for us in our brain, which controls our sight, in millions of separate parts, and although we do not realize it, all these details are seen separately. This is what happens when we look at something. Beams of light of different degrees of intensity, re-fleeted from all parts of the object, strike the lens of the eye. The lens then gathers together the spots of light from these beams and focuses them on to a light-sensitive plate-the retina-at the back of the eyeball. In this way, an image of the object is produced on the retina in the form of a pattern of lights. The retina contains millions of minute light-sensitive elements, each of which is separately connected to the brain by a tiny fiber in the optic nerve. These nerve fibers, working independently, pick out minute details from the image on the retina and torn the small spots of light into nerve impulses of different strengths. They then transmit these impulses to the brain. They do this all at the same time. All the details of the image are fed to the brain, and as we have taught our brain to add them together correctly, we see a clear picture of the object as a whole.
    Television, which means vision at a distance, operates on a similar principle. A television picture is built up in thousands of separate parts. Beams of light reflect from the subject being televised strike the lens of the television camera, which corresponds to the lens of the eye. The camera lens gathers together the spots of light from these beams and focuses an image of the subject on to a plate, the surface of which is coated with millions of photo-electric elements sensitive to light. The spots of light forming the image on the plate cannot be transmitted as light. So they are temporarily converted by an electronic device into millions of electrical impulses ; that is, into charges of electricity. These electrical impulses are then sent through space on a wireless wave to the homes of the viewers. They are picked up by the aerials and conveyed to the receivers to the television set. There, they are finally converted back into the spots of light that make up the picture on the television screen.
Which process is correct to make up pictures on the television?
选项 A、beams of light-lens of the television camera-an electronic device-electric impulses-aerials-receivers-pictures
B、beams of light-lens of the television camera-a plate-an electronic device-electric impulses-receivers-aerials-pictures
C、beams of light-a plate-an electronic device-aerials-electric impulses-receivers-pictures
D、beams of light-lens of the television camera-a plate-an electronic device-electric impulses-aerials-receivers-pictures
答案D
解析 本题考查对文章的整体理解分析能力。文中第三段介绍了电视机成像的整个过程：光束射到电视摄像机中的透镜上，透镜将其中的光点聚集到一个盘状物上并成像。图像通过一个电子装置转化为电脉冲信号，脉冲信号通过无线电波传向千家万户。最后，经天线接收传送给电视机，电视机将脉冲信号转换回光点所成的像。
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本试题收录于： 职称英语理工类C级题库职称英语分类
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