Cómo utilizar imanes (Using Magnets)

Most of the Earth's changes happen over millions of years, but earthquakes can force significant changes to the land in just a few moments. Readers will learn the science of plate tectonics and its role in the development of earthquakes around the globe. They will also learn that not all rocks are created equal. In fact, rocks are all different ages! This Spanish-translated book concludes with images of the damage and destruction that earthquakes can cause.

Do you know what the Liberty Bell is? Go back in history to understand why Americans fought for freedom from Britain, why the Liberty Bell was important to that time, and more in The Liberty Bell.

Los contenidos de este libro se corresponden con los de la unidad formativa 0152, del módulo "Montaje de instalaciones solares fotovoltaicas", perteneciente al certificado de profesionalidad "Montaje y mantenimiento de instalaciones solares fotovoltaicas". Este libro se ocupa de la parte mecánica del montaje de una instalación fotovoltaica, empezando por su planificación y el aprovisionamiento de materiales y centrándose en el montaje mismo y en técnicas y procesos, como la sujeción, la impermeabilización, la colocación de paneles... 1. Organización y planificación para el montaje...

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.