|A) can focus very rapidly as pictures change||B) is quicker than the brain|
|C) can see 2 images separated only if the interval betwen seeing them is more than one-tenth of a second||D) can shut out some of the light|
The eye can see images separately only if they are exhibited at an interval of more than 1/10 of a second. In the case of a movie, the still pictures come one after the other at less than this minimum interval. So we do not see them separately but only as a continuous moving picture.