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.

¿Y si el universo no pesara nada y la materia no existiera realmente? Lo que parecería ser una duda legítima para un erudito místico de los Vedas Indios es, en cambio, un resultado embarazoso de la aplicación de la Relatividad Restringida a las observaciones obtenidas por un grupo de astrofísicos, que han medido la radiación cósmica de fondo de nuestro universo. En los albores del nuevo milenio, el satélite WMAP, más allá de proporcionarnos una medida del cosmos, nunca antes obtenida, ha creado bastantes quebraderos de cabeza respecto al concepto de universo, en el que todavía hoy ...

Tommy Fuller and his family help a runaway slave family follow the stars in the Little Bear constellation to freedom.

The I Want to Be... series gives young children a realistic insight into the working day of adults. Easy-to-read captions and color photographs of women and men from different cultures help children understand what's involved in each occupation. Young readers learn to respect the importance of doing a job well and appreciate the contributions these workers make to our life and the world around us. These books are perfect for reading alone or in group story times. They are certain to spark questions and encourage dialogue and prompt children to learn more about these occupations. Quiero ser...

Many desert animals around the world are in danger of becoming extinct. In this enlightening, Spanish-translated nonfiction title, readers will learn a few of the causes of extinction in the desert and what problems extinction causes for animals, wildlife, and humans alike. Through vibrant photos of beautiful animals and stunning facts in conjunction with informational text and useful charts and diagrams, readers will learn and understand concepts such as habit loss and learn ways that animal activists help to protect animals and their environments, as well as helpful tips to get involved in...