A simple explanation of the structure of the heart and how it works.

An explanation, illustrated by drawings, of how a baby grows within the mother from a single cell into a fully formed human being.

On a visit to a natural history museum, a little boy sees fossilized skeletons of dinosaurs and learns what archaeologists havediscovered about the physical appearance and habits of these huge, extinct creatures.

A brief introduction to the importance of oxygen in maintainingplant and animal life.

Explains how fossils are formed and what they tell us about the past.

Explains in simple terms what happens during a solar eclipse.

Explains the basic properties of skin, how it protects the body, and how it can vary in color.

A simple introduction to caves, their formation, past uses, anddistinguishing features.

A simple description of how corn was discovered and used by theIndians and how it came to be an important food throughout the world.