Catalog Search Results

Briefly describes how our eyes work, various vision problems, and how glasses can help us see better.

Describes the structure and function of our teeth and the importance of taking care of them.

Briefly describes how the forces of lift and thrust are used to overcome gravity and resistance to enable airplanes to fly.

Briefly describes several kinds of ships and the forces that cause them to float or sink.

Explains, in simple terms, the reasons for skin color, how it is determined by heredity, and how various environmental factors affect it.

Explains why the moon changes from crescent to full moon every twenty-nine and one-half days.

Briefly describes how toilets are used to get rid of waste and how sewage is treated.

Explains the nature of meteors or "shooting stars" and how they are different from real stars.

Discusses why certain animals have become endangered and what can be done to help them from becoming extinct.

Discusses how modern whale hunting methods have caused many species of whales to become endangered and what can be done to help protect the whales.