Primavera

Get a close-up look at animals in the zoo, from appearance to behavior to babies. This series uses vivid photos to compare life in the wild and life in captivity in terms of habitat, activity, and diet.

La historia de la ciencia en la Edad Media es, hasta el siglo X, la del mantenimiento precario de los escasos saberes de la Antigüedad clásica que habían sobrevivido en occidente. A partir de entonces, la traducción del árabe de las obras de autores griegos fue la tarea fundamental. En el siglo XIII aparecen los primeros matemáticos medievales realmente creadores - Fibonacci, Jordano Nemorario y Nicolás de Oresme, entre otros. Al estudio de la obra de estos científicos y la de sus precursores está dedicado este libro.

Introduces the life of Shoshoni Sacagawea, from early childhood through her days guiding the Lewis and Clark Expedition through the American wilderness, and speculates on her life after that adventure.

Introduces readers to reptiles and the concept of classes of animals. Simple text describes the common features and behaviors of reptiles as well as offering many examples of creatures in this group.

Highlights the life and political career of the forty-fourth president of the United States who, after years of struggling with his identity and place in society, found his niche in public service and made history as the first African American U.S. President ever to be elected.