Describes the various parts of the human circulatory system and explains how and why blood is circulated throughout the body.

Describes some of the earth's natural resources, their importance, and how they can be safeguarded.

How's the weather on the Moon? There is no weather! Discover more true and surprising facts about the moon. Includes a map of the moon's cool paces, time lines, drawings, photos--and a peek at an astronaut's space suit.

"Learn how animals can be trained to assist people with a variety of different jobs."--