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.

Bienvenido a Dinosaurium. Nuestro museo está abierto a todas horas. Sus salas albergan una extraordinaria colección de criaturas del Mesozoico, desde el pequeño troodón hasta el gigantesco braquiosaurio. Aprende cómo evolucionaron los dinosaurios y por qué unos tenían plumas y otros, escamas. Entra y explora el reino de los dinosaurios en todo su esplendor.

Narwhals are often called the "unicorns of the sea." But these fascinating creatures are members of the whale family. Read all about narwhals as you practice addition. 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 addition 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...

What has a head, two tails, and shoots across the sky? A comet. Coming from the far edges of the solar system, most comets travel around the Sun, while meteors appear as flashing streaks of light in the night sky. Explore these amazing celestial wonders as they zip through space! This book looks at the difference between comets and meteors and their effects on Earth. The physical characteristics of each are identified in detail. This book won’t come crashing down! It’s filled with fun facts that give additional information on this exciting science topic. This book allows students to use...

A todos nos gustan los piratas: Sus rostros feroces, sus patas de palo, sus mapas y sus tesoros hacen volar nuestra imaginación. Pero, además, los piratas pueden ser muy divertidos... ¿No te lo crees? Lee Versos piratas, piratas en verso y lo comprobarás. Ana Alonso, poeta y escritora, nos ofrece un «manual» de piratería en verso a través del humor: Ironía, disparatados juegos de palabras y adivinanzas son algunos de los recursos expresivos que componen esta minuciosa descripción del universo pirata. Pero Versos piratas, piratas en verso es también un libro de piratería en...