¿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.

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.

Este libro reflexiona sobre la obra de Wifredo Lam y Manuel Mendive, dos de los ms grandes pintores cubanos del siglo XX, y sus relaciones con la cultura popular afrocubana. En un extenso y documentado recorrido, su autora devela los vnculos entre los sistemas adivinatorios africanos, los cultos a los orishas y las tradiciones secretas presentes en las obras de Lam y Mendive.

Un libro de referencia para todas las preguntas que chicos y chicas se hacen sobre el sexo, aunque les resulta incómodo hablar de ello. Con textos escritos por profesionales, serio, riguroso, pero al mismo tiempo ameno y divertido. Porque la mejor protección es la información.

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...

Madame Olenska anuncia a Zoe y a sus compañeras que podrán empezar a utilizar zapatillas de punta antes de lo previsto en el programa. Es como crecer demasiado rápido: da vértigo y asusta al mismo tiempo. Mientras Jonathan crea su primera coreografía y experimenta los primeros celos, Zoe se enfrenta a una duda importante: ¿tiene de verdad talento para la danza? Y si la respuesta es que no, ¿qué hará con su vida?