La antigua Roma (Ancient Rome)

Wind Power: A waving flag, blowing leaves, a kite soaring through the skyall are moved by wind power. Wind is also our fast-growing source of energy. Find out how wind forms and the different ways we may use it in the future.

Recess is a time to go outside, have fun, and play. Spend some time problem solving to make sure everyone has fun at recess! This Spanish math book combines math and reading skills and uses real-life examples of problem solving to teach subject-area content. The dynamic images, detailed sidebars, practice problems, and math diagrams make learning problem solving easy and fun. Text features include a table of contents, a glossary, an index, and captions to build vocabulary and increase understanding of math and reading concepts. An in-depth problem-solving section provides additional learning...

* ¿En qué punto nos encontraríamos si no existiesen la rueda o el vidrio? Imagine la vida sin el cemento o los ordenadores. * Piense durante un momento cómo mejoran nuestra salud y nuestro bienestar las vacunas y el marcapasos. * La sofisticación de la medicina contemporánea es una proeza excepcional que permite a muchas personas vivir con unos niveles de atención sin precedentes. * Pero el progreso médico tiene un precio que también forma parte del paisaje médico actual: resistencia a los antibióticos, bacterias multirresistentes que mutan constantemente y las consecuencias...

[English] What is the difference between a savanna and a prairie? How do bison, zebras, and other grazers avoid hungry grassland predators? Trek across the plant-covered landscape of this book, and find out what makes grasslands one of Earth's treasures. [Spanish] ¿Qué diferencia hay entre una sabana y una pradera? ¿Cómo escapan los bisontes y las cebras de los depredadores? Camina entre los altos pastos de este libro. Descubrirás por qué los pastizales son uno de los grandes tesoros de la Tierra.

Our closest solar system is about 10 light years away. It has two main types of planets. Some are rocky and small, like planet Earth, while others are huge balls of gas, like Jupiter. Learn about how astronomers once thought our solar system was the one and only, to how they have now discovered hundreds of stars with planets orbiting them, which means there could be billions of solar systems in outer space! Just maybe, these alien worlds could host life, like our own amazing planet. This book allows students to use observations of the Sun, moon, and stars to describe patterns that can be...