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This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute...

Gente que hay que conocer is a series of biographies designed for beginning readers. Each book introduces one of the most important individuals in recent times and explains what makes her or him so remarkable. People We Should Know, a companion English-language edition, is also available.

Readers won't have to disassemble their favorite toys to discover what makes them work. This book explores electric, magnetic, and motion-powered toys from design to function. It introduces readers to the six simple machines and explains how they use force and motion to do work. Not every toy is a technological marvel. Readers learn about time-honored favorites including the rocking horse, Slinky, and rattles.

El 11 de febrero de 1990, después de haber luchado toda su vida contra el Apartheid y tras 27 años en prisión, Nelson Mandela fue finalmente liberado. La historia de Mandela, que finalmente se ha convertido en uno de los más grandes líderes mundiales, es también la difícil historia de Sudáfrica.