¿Por qué hibernan los animales? (Why Animals Hibernate)

The rock cycle has been taking place for millions of years. However, geologists have only known about this phenomenon for about 300 years. Young terrestrial explorers are introduced to different types of rocks, where in the cycle these rocks fit, and where in Earth's layers each step takes place. Fact boxes provide readers with fun additional information. A diagram helps readers make sense of the new information they're learning.

When rocks change because of environmental conditions, the new rocks are called metamorphic rocks. A rock's chemical or physical makeup may change because of conditions such as temperature, stress, or pressure. Your readers will learn fascinating facts including where metamorphic rocks are most commonly found, the different types of metamorphism, and how metamorphic rocks are identified. Full-color photographs depict these rocks in nature. A helpful graphic organizer shows how these fascinating rocks form.

Although Earth is mostly made up of igneous and metamorphic rock, sedimentary rock covers about 75 percent of Earth's land surface. This means it's the most visible kind of rock on Earth. Sedimentary rocks form when sediment accumulates and compacts. Your readers will learn how sedimentary rocks form, the different types of sedimentary rocks, and how people use sedimentary rocks. Fun fact boxes provide readers with additional information. A helpful diagram illustrates how sedimentary rocks form.

El ADR es un documento extenso y tedioso. Por ello resulta imprescindible entender su estructura para asi poder convertirse en una herramienta sencilla de manejar. Expedidores, ambaladores, cargadores/llenadores, transportistas, descargadores y explotadores de cisternas asi como los Consejeros de Seguridad para el transporte por carretera tiene la obligación de formar cualquier empleado que intervenga en operaciones de expedición, embalaje, carga, transporte y descarga de mercancías peligrosas por carretera.

It was September 14, 1814, and America and Great Britain were at war. Frances Scott Key watched from the deck of a British ship, where he was being held captive, as cannons exploded around them. After 25 hours, the fighting ceased and Key peered through the clearing smoke, looking for some sign as to the outcome of the battle. Was the American flag still flying? His wartime experience inspired Key to write a poem, which was later set to music and became America’s national anthem. This book tells the story of the inspiration behind our national anthem, which helped transform the flag into a...

Heredero de la gran tradición norteamericana en narrativa de terror, que nace con E.A. Poe y pasa por H.P. Lovecraft, Stephen King ha logrado con sus obras una difusión jamás alcanzada por ningún otro autor en este género, dotándolo de una vitalidad envidiable. Danza Macabra (1981) es un lúcido y divertido ensayo, lleno de referencias a multitud de obras y jugosas anécdotas biográficas, que pretende dar respuesta a la paradoja esencial del aficionado a la ficción de terror: «¿Por qué hay personas dispuestas a pagar a cambio de sentirse extremadamente incómodas?» Y para abordar...

Además de la violencia ejercida sobre los opositores y la instauración de un modelo que ponía en el centro de la vida social al mercado, la dictadura de Pinochet se empeñó en forjar una juventud que permitiera proyectar el “nuevo orden” por medio de organizaciones civiles que dieran pie, a medida que estos jóvenes crecieran, a partidos políticos, organizaciones empresariales, think tanks y universidades. Fue la primera vez en la historia de Chile que se instituyeron “juventudes de Estado”, a la manera en que lo hicieran los gobiernos de Mussolini en Italia, Salazar en Portugal...