Hudak, Heather C.

"This ... title introduces readers to the concept of a wave and the patterns and properties common to both light and sound waves. Clear text and detailed diagrams combine to demonstrate the cause-and-effect relationships involved in the properties of amplitude, wavelength, and frequency. A link to interactive activities online plus an activity in the book allow readers to explore key concepts close up by creating their own wave models."--.

Australia es el continente m?s peque?o del mundo. Tiene aproximadamente el mismo tama?o que los Estados Unidos. La Gran Barrera de Coral de Australia tiene m?s de 1.500 millas (2.500 kil?metros) de coral. M?s informaci?n en Australia. Combina im?genes impresionantes con hechos interesantes para ofrecer una visi?n de la tierra, la econom?a y la historia de cada continente.

Learn fun facts about Australia, from its early history to its current politics and culture.

Throughout history, people have always traded goods in exchange for others. This is a form of spending that continues in economies around the world when people exchange cash or credit for products and service.

"False information and censorship significantly impact how people interpret issues and events. This important title examines the different ways of, and reasons for, controlling information, and how to build information literacy"--Provided by publisher.

". . . looks at the facts, viewpoints, and perspectives surrounding vaccines and how they became a crossroads between science and individual rights"--Back cover.

Paul Bunyan is a legendary lumberjack and works alongside Babe the Blue Ox in stories. This title explores the history and cultural significance of these figures. Easy-to-read text, vivid images, and helpful back matter give readers a clear look at this subject.

"Cuba . . . is a . . . tourist destination due to its subtropical climate and beautiful coastline. Read all about the country's land and resources, its complicated political history, and the impact of colonization by Europeans, as well as daily life and culture today for people across Cuba"--Back cover.

"How can African wild dogs hunt animals ten times their size? What does the howl of a coyote mean? Why do some solitary hunters live in packs? Discover the answers in this . . . book and learn about the many ways living in a pack helps animals survive"--Provided by publisher.

"Why do gorilla troops move to a new area each day? Why do bonobos sleep in large groups? How do animals in a troop help raise young? Discover the answers in this . . . book and learn about the many ways living in a troop helps animals survive"--Provided by publisher.