When it is dark you can only see shapes. Light rays bouce off objets and go into your eyes. The iris is the colored part of your eye the black part of your eye is called your pupele. Your eyes when you look at something your eyes make a picher in the back of your eyes.
Book Title: You and Your Body
a human life begins with a cell. Inside each cell makes a uniqe person. You have 206 bones in your body. Your heart is the size of your fist.
Book Title: Your Nervous System
If you didn't have Nervous System you would not be able to do anything.