翻译When you watch a movie in the cinema, you may wonde

翻译When you watch a movie in the cinema, you may wonde
When you watch a movie in the cinema, you may wonder “how moving picture” is made and where the voice, noise and music come form. Now is the answer.
　　In the 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, appear on the screen, and we see it. Then the light is covered and next photograph is move to the position in front the strong light. Meanwhile（同时）, 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 noting on the screen actually moves. “The moving picture” is in fact made of a lot of bits. We see about 86,400 different pictures every hour, but none of them moves.
　　The voices, noises and the music are recorded on the side of the cinema film. The record looks marks of strange shapes. The side of the film passes in front of another light, and the rays（射线） 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（认为,考虑） as “printed sound”.