Por qué?

Al final de cada página de este libro ilustrado, el lector tiene que elegir entre dos caminos a seguir por el protagonista, creando así su propia aventura. Los personajes y las situaciones de los cuentos tradicionales se entrelazan en un laberinto de 1001 posibles historias.

When people go to sleep, bats are just waking up. While young readers may recognize the image of bats in the night skies, where they live may be less familiar. This title takes readers inside bat roosts to uncover the fascinating facts about this creature. Readers will learn the basics of bat roosts—in caves and beyond—and how they help bats survive in the wild. The text also looks at bat’s appearance, behavior, and the crucial role they play in nature’s ecosystems—topics covered in most elementary science curricula. Diagrams, fact boxes, colorful images encourage learning.

Explains the basic science of flight, the problems of getting vehicles into the air, different types of engines, and aircraft design, and includes instructions for making aircraft models.

Tackle today’s toughest races while learning fractions! Marvel as contestants around the world climb, crawl, run, and jump through the world’s toughest marathons and obstacle courses. This Spanish book combines mathematics and literacy skills, and uses practical, real-world examples of problem solving to teach math and language arts content. Students will learn fractions while engaged in reading high-interest 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...

¿Qué sucedería si se mezclaran los avances tecnológicos del siglo XXI con los poderes ocultos de la ouija? ¿Qué peligros esconden la nanotecnología y la ouija virtual realizado a través de internet? Una empresa dedicada a investigaciones con tecnología espacial, revoluciona el mundo con inventos para acabar con el cáncer mediante la nanotecnología, evitar accidentes de tráfico con su red de carreteras inteligentes, curar enfermedades psicológicas con realidad virtual o hacer viajar la electricidad por ondas, convirtiendo a los cables y enchufes en pequeñas piezas de museos. El...