Exploremos el ciclo de la roca (Exploring the Rock Cycle)

When winter hits, many people in colder climates spend most of their time indoors. But what do wild animals do? Some animals spend winters hibernating. Beginning readers will learn what hibernation is, why some animals hibernate and others don't, and how hibernating animals prepare for their long sleep. Full-color photographs grab readers' attention and allow them to draw connections to the narrative. Readers will love learning about this mysterious, restful time in some animals' lives.

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.

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.

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 ...

Provides information on the tiny reptiles, including their use of color as a defense, their climbing skills, and their ability to grow back a missing tail.

Esta obra pretende desarrollar la comprension estrategica del jugador y asi permitirle mejores resultados.

Cuando llega la hora de dormir, ¡los monstruos tienen miedo! Y todos quieren meterse en la cama de Joaquín. Pero Joaquín está muy incómodo y no puede dormir con tanto monstruo miedoso en su cama.