题目内容：

When you watch a movie in the cinema, you may wonder how “the moving pictures” is made and where the voices, and noises and music come from. Now here is the answer.

In modern times, the middle part of a cinema film has lots of small photographs, each one of which is different from the one before it. Each photograph is brought in front of a strong light, and there it stops for a very small part of a second. This photograph, therefore, appears on the screen, and we see it. Then the light is covered and the next photograph is moved to the position in the front of the strong light. Meanwhile, the metal cover turns away from the light. Thus, the second photograph is shown on the screen. This is done again and again, twenty-four times a second, and we think we are watching a moving picture on the screen. But nothing on the screen actually moves. ”The moving picture” is in fact made up of a lot of bits. We see about 86,000 different pictures every hour, but none of them moves.

The voices, noises and music are recorded on the side of the cinema film. The record looks like marks of strange shapes. The side of the film passes in front of another light, and the rays of light which pass through change as the marks change. These marks have been made from the voices and other sounds of the people and events in front of the cinema when the film is being made. The marks may be considered as “printed sounds”.

1. When a cinema film is shown, how long does each photograph appear on the screen?

A. One twenty-third of a second.

B. One twenty-fourth of a second

C. A few seconds

D. One thirty-fifth of a second.

2. Why can we see pictures moving on the screen?

A. We see about 86,000 different pictures every hour.

B. Each picture is a little different from the former.

C. Photographs change quickly.

D. Both B and C.

3. What is a cinema film made up of?

A. Small photographs and a strong light.

B. Small photographs and the sounds.

C. A lot of bits.

D. Voices and photographs.

4. Which is the true about the sound record?

A. It sounds strange.

B. It looks as irregular marks.

C. It is printed in the middle of a film.

D. It is made while the film is being shown on the screen.