Los estados de la materia — Los gases

Each year, Martin Luther King Jr. Day serves as a reminder of the life and work of one of America's greatest civil rights activists. In this informative book, readers will learn about the importance of the civil rights movement and why we celebrate Martin Luther King Jr. Day. Full-color photographs accompany the text. This essential book features accessible language that is ideal for children in the early stages of learning to read.

Reveals the truth about cannibalism in pre-Columbian America, avoiding sensationalism and opting for historical accuracy on a matter that has been subjected to all sorts of misinterpretations as well as mistaken beliefs.

Un canto a la libertad, el amor y la amistad. Este libro recrea la vida de Hipatia de Alejandría, una figura capital de la antigüedad y protagonista del filme Ágora, de Alejandro Amenábar. Estuvo versada en filosofía, matemáticas y astronomía, pero su clase magistral para la historia fueron su sed de vida y de conocimiento, así como el valor y la entereza para defender sus ideales de convivencia y tolerancia. Hipatia fue un espíritu libre, una voz incómoda a causa de la férrea voluntad de llevar una vida plena como mujer sin pedir perdón por ello, aunque debiera pagar por ello el...

This book is a comprehensive, practical presentation of the principles of behavior modification and guidelines for their application. It teaches forms of behavior modification ranging from helping children learn necessary life skills to training pets, to solving personal behavior problems.