Describes the designs and symbolism of the flags that represent the fifty states and the District of Columbia.

Presents an introduction to the U.S. Army, discussing the history and purpose of the land-based branch of America's armed forces, the work of the Army in war and peace, the command structure, and what life is like in the Army. Includes a look at Army weapons.

This book presents a description of and background information about the flowering plants that have been chosen to represent the fifty states and the District of Columbia.

Describes the construction, purpose, and parts of dams throughout the world.

This book provides a simple discussion of the causes of air movement, uses of wind power, and such phenomena as hurricanes and tornadoes.

Examines the history, varieties, and uses of trains.

This book provides a simple discussion of sound waves, frequencies, and the uses of radar and sonar.

Discusses the nature, history, and building of skyscrapers.

Describes the behavior of whales, with an emphasis on their hunting, communication, and travel.

Examines the work, equipment, and personnel of airports.