Alimentos

Imagine traveling at half the speed of a jet plane without ever leaving the ground! Students will discover the technology that makes such speeds possible, from special tracks and safety precautions to aerodynamically designed trains. What are the limits to the speed of trains? What imposes those limits? Students also will read about the future of passenger train travel, from flying trains to trains that use huge magnets to levitate inches or centimeters off the track. Some trains safely reach speeds of more than 200 mph!

Mysterious ancient ruins, hidden deep in the jungle of southern Mexico In May 1840, explorers John Stephens and Frederick Catherwood road their mules along a steep, muddy jungle path. They were hoping to find the ruins of an ancient, deserted site in Mexico they knew only from visitors’ accounts. Through the trees, they spied the remains of a crumbling stone palace. Palenque! In the weeks they spent there, the men discovered intricately designed buildings and mysterious glyphs, or symbols. Who built this city? What did the glyphs mean? The questions remained largely unanswered until the...

Storms are a fascinating topic and a great way to get young readers interested in science. This series uses simple text and dramatic, full-color photos to take students inside nature's powerful and deadly storms. Each book explains one kind of storm- what it looks like, how it forms, the damage it can do, and how people can protect themselves from danger.

«Mi vida no me interesa en absoluto», solía decir públicamente André Malraux (1901-1976). Pero, de hecho, sólo le interesaba su vida, que concebía como una obra y que quizá sea su mejor novela. Así es como la aborda Olivier Todd , que en esta biografía exhaustiva la recorre sin complacencia ni agresividad, pero con la intención de que ninguna de las preguntas que suscita Malraux , como novelista, intelectual, político y personaje público, quede sin respuesta. ¿Fue realmente desgraciada su infancia, que él decía odiar? ¿Llegó a ser un revolucionario? ¿En qué sentido?...