El ciclo del nitrógeno (The Nitrogen Cycle)

"Pterodactyls are one of the most fascinating ancient creatures. Now in Spanish, this carefully leveled text includes fascinating facts about these fancy flyers in an accessible format. Diagrams, age-appropriate critical thinking questions, and other features inspire visual learning and engagement."

What’s the difference between a seal and a sea lion? These “second cousins” of the sea look similar, but there are many ways to tell these creatures apart. From ear shape to the noises they make to communicate, seals and sea lions are amazing creatures with both shared features and many truly unique attributes. They both share an ocean habitat, but when readers take a closer look, it’s easy to discover how they each fight off predators, mate, and raise their young in different ways. Captivating full-color photographs help to bring these marvelous mammals to vivid life.

Introduces the life and times of Underground Railroad and anti-slavery leader Harriet Tubman and explains her place in American history.

El libro ofrece un material para aprender español de forma novedosa, utilizando los planteamientos recogidos en el Marco común de referencia y en los Niveles de referencia para el español, que permiten ayudar al alumno a conocer, comprender y utilizar el español de forma práctica. Está constituido por seis módulos. Cada módulo está formado por los cuatro ámbitos de uso de la lengua (Ámbito personal, Ámbito público, Ámbito profesional y Ámbito académico) para poder utilizar la lengua de una manera más adecuada a cada situación. Propone un aprendizaje activo, dinámico y...