¿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.

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.

Presents the life story of the Mexican-American labor leader who helped achieve justice for migrant farm workers by creating a union to protect their rights.

Esta divertida y originalísima novela sobre una saga familiar escandinava constituyó el acontecimiento editorial del año 2005 en Dinamarca, donde además de obtener un notable éxito de público —más de cien mil ejemplares vendidos— fue galardonada con los premios más importantes, entre ellos Autor del Año, Libro del Año y el Golden Laurel, concedido por los libreros de aquel país. Después de pasar unos años en Ámsterdam intentando abrirse camino como pintor, Asger regresa a Dinamarca para despedirse de su abuela Bjørk, que está a punto de morir. De esta manera, el joven se...

Pets! We love them, and we take good care of them. Learn all about what Guinea Pigs need to be happy and playful pets. ¡Las mascotas! Las amamos y las cuidamos mucho. Aprende todo sobre qué necesitan los Cobayos para estar felices y ser mascotas juguetonas.

Simple text and photographs describe the life of Michelle Obama. Michelle Obama became First Lady on January 20, 2009. But before she lived at the White House, she was a powerful lawyer. Learn about her childhood, education, and goals as first lady of the United States.