1. Without the , we could not walk without staggering.

2. Different patterns are recognized as different sounds; in the case of speech, these are referred to as .

3. A classic study by the Russian psychologist (1967) shows how we move our eyes when looking at a visual object.

4. If you make the hole bigger in a to let more light through, the image becomes fuzzy, or blurred, because more than one direction of incident light can land on a given point on the back surface.

5. gets reflected or absorbed by surfaces.