Energía del viento

Defines screws, explains their functions, and suggests simple experiments to demonstrate how they work.

Follows the life and career of the French scientist who proved the existence of germs and their connection with diseases.

Defines levers, explains their functions, and suggests simple experiments to demonstrate how they work.

Dragonflies are large flying insects known for their brightly colored bodies and see-through wings. They are among the fastest insects in the world. Learn more about these amazing animals in Dragonflies, a Fascinating Insects book.

Más de 150 fotos y textos sencillos para descubrir de dónde salen los alimentos que compramos en las tiendas.

Black holes are neither holes nor black. They're invisible and packed with matter! Future astronomers will find out many more fascinating facts about these space phenomena with this intriguing book. Carefully crafted text encapsulates the most important information about black holes, such as how scientists locate them and their significance in a star's life cycle. Amazing photographs support critical concepts and inspire a true appreciation of the spectacles of space.

Learn about the Victorian era while building your knowledge of equivalent fractions! Students will learn fractions while engaged in reading about the innovations of the Victorian era. This Spanish book combines mathematics and literacy skills, and uses practical, real-world examples of problem solving to teach math and language arts content. The glossary, index, and table of contents will further understanding of reading and math concepts, and the full-color images, practice problems, and math graphs and charts make learning math easy, practical, and fun. The Explore Math sidebars and Math...