A simple explanation of how the rotation of the earth causes night and day.

Introduces teeth, describing how many we have at various stages of life, why they fall out, and what they do.

Describes the characteristics of snow, its usefulness to plants and animals, and the hazards it can cause.

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

Describes mushrooms, molds, and other fungi and their function in the cycle of growing things.

Explains in simple terms what happens during a solar eclipse.

Describes the physical characteristics, behavior, and reproduction of a few of the world's 2,700 kinds of earthworms.

Introduces the way in which the sun's relationship to the earth is responsible for seasonal changes.

Discusses prehistoric birds and their ancestors and theories on how creatures began to fly.

Easy-to-understand text explains the mechanics of bird flight.