Somervill, Barbara A

Provides an introduction to mass and weight, examining how it is measured and the history of measuring systems.

This book describes the challenges that Africanized honey bees pose in South America and North America and what has been done to monitor the movements of Africanized bees and attempt to stop their invasion of new territory.

Presents a short history of the computer examining the ancient abacus and slide rules, early computers, ENIAC, the silicon chip, and more.

"Empire of the Aztecs" opens with a summary of the rise and fall of the empire, placing it within the context of its time period and geographical location. The second half of this book explores the daily lives of the Aztec people, focusing on their social customs, religious practices, family and community structure, and cultural accomplishments.

Introduces students to the natural history of the gray wolf, describing its habitat, behavior, and threats to its existance, and explores how people are trying to save it from extinction.

Describes the characteristics, behaviors, and life cycles of American bison, explains some of the reasons why the animals were slaughtered in the late nineteenth century, and discusses the efforts of conservationists to restore American bison populations on protected reserves and ranches.

A brief biography of Catherine de Medici, wife of King Henry II, providing information on her childhood, her experiences in the court, and her influence on French history.

Introduces the geography, topography, and climate of the continent of Australia.

Examines how the body's organs and systems work together and how to keep the body fit and healthy.