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

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.

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.

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.

Mateo Chamero es un niño obeso de ocho años al que su madre quiere obligar a adelgazar. Su compañera de pupitre, Ana, está muy enferma. Mateo quiere ayudarla, pero no sabe cómo. ¿Encontrará el modo de hacerlo? Una estupenda historia que resalta los valores de la amistad y la superación de dificultades.

Los Cuadernos Everest de Lengua son un excelente apoyo para trabajar los contenidos abordados en el área de Lengua.

Esta obra tiene como finalidad permitir al lector la fácil identificación de algunas de las plantas nativas o naturalizadas de las Salinas y Perisalinas del Chaco Árido. Se ha tenido en cuenta que la utilizará público culto, docentes, estudiantes, amantes de la naturaleza, productores, etc., que en general no tiene formación botánica. Es por eso que se ha tratado de evitar los términos técnicos, aunque esto no siempre ha sido posible. Asimismo se consideró que los trabajos botánicos mayormente llevan una cantidad de información solo útil para futuras investigaciones en taxonomía ...

Describes what early planes and air travel were like, how planes were developed to travel faster, and presents some pioneers of aviation.