Cómo podemos utilizar el tornillo?

Defines pulleys, explains their functions, and suggests simple experiments to demonstrate how they work.

This inspiring biographical series ties in with elementary history, science, and social studies curricula, providing teachers with a valuable interdisciplinary resource. With these books, young readers will discover historical figures who devoted their lives to making the world a better place, and changed the course of history. Text copyright 2004 Lectorum Publications, Inc.

The Uses Of Wind Energy Is The Topic Of This Book. Explains The Positive And Negative Impact This Form Of Energy Can Have On Our World.

A bilingual collection of poems in which the Mexican American poet celebrates winter in northern California and the experience of growing up bilingual and bicultural.

Explores The Number Twelve With Relationship To Time, Counting, And Things That Are Sold By The Dozen.

Llega un momento en la vida en que nos damos cuenta de que lo que importa son las cosas que no se pueden ver, y que las que sí están a la vista no siempre son lo que parecen. El amor es todo y no podemos limitarnos a sentir sólo partes de una fuerza tan grande. Si devuelves el amor que hoy recibas con un detalle desde el fondo de tu corazón, algún día todo lo que has dado te será devuelto, y entonces sabrás por qué estás aquí.

Mysterious ancient ruins, hidden deep in the jungle of southern Mexico In May 1840, explorers John Stephens and Frederick Catherwood road their mules along a steep, muddy jungle path. They were hoping to find the ruins of an ancient, deserted site in Mexico they knew only from visitors’ accounts. Through the trees, they spied the remains of a crumbling stone palace. Palenque! In the weeks they spent there, the men discovered intricately designed buildings and mysterious glyphs, or symbols. Who built this city? What did the glyphs mean? The questions remained largely unanswered until the...