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

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.

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.

Uncovers the secret codes that different animal species use to relate to each other, revealing that communication among certain animals is not different from human communication.

Siervos medievales presenta una realidad social poco estudiada hasta ahora por la historiografía medievalista: la vasta extensión de la dependencia campesina de carácter servil en el norte de la Península y, en especial, en Aragón y Navarra, durante los siglos XI al XIII. Indaga la experiencia vital de los siervos, las características de la reproducción social de las familias serviles y la dinámica de la dominación ejercida por los señores. Muestra la ambigüedad de los estatutos, del deshonor que pesaba sobre los siervos y las características de la resistencia campesina. El...

Mas de cuarenta anos de amistad complice avalan al critico Tullio Kezich en la tarea de abordar desde la cercania, a veces desde la indiscreta intimidad, la biografia de Fellini. Con rigor, una prosa agil y una documentacion exhaustiva, Kezich desmiente innumerables leyendas que rodean su figura; revela facetas poco conocidas, como su gusto por las ciencias ocultas o sus devaneos con el psicoanalisis; arroja nueva luz sobre su relacion con las mujeres, con especial atencion y tacto a sus cincuenta anos de monogamia a la italiana con la inolvidable Giulietta Masina; repasa las vicisitudes de...

This book uses intriguing primary sources to teach students about rules and why following them is important. The primary source images and simple sentences will engage students in reading and build their social studies content knowledge. For use in the classroom or at home, this Spanish book includes a simple glossary and index to introduce informational text features to young readers and provide additional reading support.