The television camera is rather like the human eye. Both the eye and the camera have a lens(镜头),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 what 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(强度), reflected 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(视网膜) 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 fibre in the optic(视力的)nerve. These nerve fibres, working independently, pick out minute details from the image on the retina and turn the small spots of light into nerve impulses(冲击)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 reflected from the subject being televised strike the lens of the television camera, which corresponds to(相当于)the lens of the eye. The camera lens gathers together the spot 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.

 

72. In the first paragraph, we are told that the television camera is like the human eye in__________________

A. one way                         B. two ways

C. three ways                      D. a large number of ways

73. Which of the following is NOT true according to the writer?

A. The eye produces a picture on a screen.

B. Our sight is controlled by our brain.

C. We see all the details of an object in one piece.

D. The picture is made up of millions of spots of light.

74. All the rays of light reflected from objects are______________

A. of the same intensity                 B. not at all intense

C. to some degree intense              D. of varying intensities

75. A camera lens focuses an image on to_____________.

A. the subject                    B. a surface made up of millions of light sensitive elements

C. a television set               D. millions of photo electric beams of light

 

When a cat is frightened, its heart starts beating faster, its muscles get tense, and there are changes in the chemicals in its bloodstream. If the danger continues, it will defend itself, or it will run away as fast as possible.

Something like this also happens to people. When we are excited, angry, scared or aroused(冲动) by others' emotions, our bodies go through many physical changes, all of which make us more alert(警惕的) and ready to react. We also get ready to defend ourselves or run. Human beings, however, have a problem that animals never face. If we give way to our feelings and let them take over, we can get into trouble. Have you ever said something in anger ―― or hit somebody ―― and regretted it later? Have you ever shouted at a teacher, told somebody you were lonely, or said you were in love, and then wished later you had kept your mouth shut? It isn't always wise to express your feelings freely.

Does this mean that it's smarter always to hide our feelings? No! If you keep your feelings of anger, sadness, and bitterness hidden away or bottled up(掩饰) inside, your body stays tense. Physical illnesses can develop, and you can feel disturbed badly inside. It can actually be bad for your health.

You can try to treat emotions as if they were bananas in the cupboard. You can hide them and you can pretend they don't exist, but they'll still be around. And at last you'll have to deal with them, just like those bananas.

 

68. By taking a cat as an example, the author wants to show us that__________

A. animals can't control their feelings

B. people can't control their feelings

C. people's physical reactions are like those of animals in a way

D. people's bodies go through many physical changes in certain situations, too

69.It's mentioned in the text that human beings get into trouble because_____

A. we are not as alert as animals

B. we sometimes can't control our feelings

C. we always do something wrong to other people

D. we don't pay attention to our physical changes

70.The author wants to tell us in the last two paragraphs that_________.

A. there's no way to deal with our feelings

B. we should put some bananas in the cupboard when we're angry or scared

C. feelings will gradually disappear when we hold them in

D. we should neither express our feelings freely nor hide the bad feelings inside

71.The author's purpose in writing this article is to_______________.

A. tell us that it's pretty good to keep our feelings inside

B. give some advice on how to express our feelings freely

C. make us deal with our feelings in a wise way

D. make us know it isn't always good to express our feelings freely

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