Introduces GPS technology, describing how the worldwide navigation system was invented, how satellites and ground stations work together, and how the technology is used by the military and civilians.

"In science fiction, time machines let people travel backwards in history and forward to the future. How could one of these time-traveling devices be created? Scientists have some ideas, which include using spaceships and black holes. Discover the science and technology behind what it would take to make a real-life time machine!"--

Economy 101 studies the basics of the free market economy, delving into details about economic growth, recessions, and government interventions. Readers will come away with confidence in discussing economic topics.

This book explores sickle cell disease and how people with the disease manage it. It examines how sickle cell affects daily life, work, and school, and it explains the latest treatments available. Features include a glossary, web resources, source notes, and an index. Aligned to Common Core Standards and correlated to state standards.

"Reptiles are fascinating, unique pets, but they require special care. Reptiles examines various reptile species and their unique needs, as well as the laws, regulations, challenges, and controversies regarding owning these animals. It also looks at the industry and communities that have sprung up to support reptile ownership and the many ways reptiles bring joy to their owners. Features include a glossary, a map, references, websites, source notes,...

Describes the daily life and activities of Mexican Americans in New Mexico during the early 1800s including information about their homes, community, and links to Spain and Mexico.

The Great Wall of China, built in many sections over many centuries, is China's best-known landmark. Engineering the Great Wall of Chinaintroduces readers to the dynasties that constructed it, explores the construction techniques that were used, and looks at how the modern Chinese government is working to protect it for the future. Easy-to-read text, vivid images, and helpful back matter give readers a clear look at this subject. Features include...

Located between the orbits of Mars and Jupiter, the asteroid belt contains objects ranging from bits of dust to rocky bodies hundreds of miles across. Studying it has helped scientists learn more about the history of our solar system. The Asteroid Belt introduces readers to this region in space and explains how people are exploring it today.