El ferrocarril transcontinental (The Transcontinental Railroad)

People today refer to the Midwestern and prairie states as flyover country. During the Civil War, crossing those areas was the biggest obstacle in uniting the East and West Coasts of our divided nation. An act of Congress in 1862 authorized the Central Pacific and the Union Pacific railroad companies to build a railroad that would link the coasts. Seven years later, on May 10, 1869, an overwhelmingly immigrant labor force completed the task when a rail line was join in Promontory, Utah. The states had become united at last.

A biography telling the life story of Revolutionary War hero and spy Nathan Hale. Written in graphic-novel format.

Using helpful charts, graphs, informational text in conjunction with vivid images and intriguing facts, this engaging, Spanish-translated title allows early elementary readers to explore the ecosystem, plants, and animals of the deserts around the world.

Dados los problemas medioambientales y económicos anejos al uso de combustibles fósiles, crece cada día el interés de formar a nuestros estudiantes en las energías renovables. Ahora bien, por experiencia sabemos que, cuando un alumno empieza a adentrarse en tales energías, se topa con ciertas dificultades sobre todo en el caso de la energía solar fotovoltaica. Ello se debe en ocasiones al desconocimiento de los fundamentos físicos de la célula solar fotovoltaica, o de las leyes que rigen la radiación solar, o de ciertas nociones básicas de electricidad... Esta obra trata justamente ...

There are lots of families, but no two are exactly the same. Conoce la familia, a fully translated Spanish edition of Meet the Family, celebrates our most precious relationships. Each title opens doors to a variety of homes and reveals the many ways people combine to form families.