[单项选择]

THE ILLUSION OF FILM

1 Film is an illusion because the moving pictures seen on the screen are not moving at all. A fihn is actually a series of tiny still pictures, or flames. They appear to be moving because the retina of the human eye retains the impression of an object for a split second after that object has actually disappeared. This principle is known as the persistence of vision. When we look at a single frame of film, the image persists in the brain’s visual center for a fraction of a second. Then, the next frame comes along and the brain has to catch up with the new image. Thus, our eyes and brain trick us into thinking that we see a smoothly moving image rather than a series of still ones.
2 Another illusion of film is known collectively as special effects, the tricks and techniques that filmmakers use when makeup, costume, and stunts are still not enough to make a scene convincing. Special effects artists apply scien
A. changes
B. operates
C. breaks
D. reverses