Electricidad - Instalaciones eléctricas

Deforestation, hunting and global warming have endangered countless species. The orangutan, okapi, giant panda and the blue whale are just some of the 30 species on the brink of extinction that are featured in this book. They need your help. The International Conservation Society illustrates how many of these species are left in the wild, and the latest status regarding their natural environment. You'll learn how you can aid endangered species and help sustain the ecosystems that give them life.

Las frases quedan colgadas en el tiempo, creadas por hombres que se equivocaron en lo que enseñan en ellas. Eres lo que puedes ser capaz de creer; que cada buen proverbio que exista sea tu mentor, tu ley, tu concepto y así serás infalible ante cualquier circunstancia, porque el verdadero poder está en el conocimiento de reconocer en lo que todos fallamos. El error más grande es no aprender de los errores, pues quien no aprende de ellos esta condenado a seguir repitiéndolos. Cuando una frase es parte de tu vida diaria, como guía, se volverá religión para ti, y así te convertirás en...

It was September 14, 1814, and America and Great Britain were at war. Frances Scott Key watched from the deck of a British ship, where he was being held captive, as cannons exploded around them. After 25 hours, the fighting ceased and Key peered through the clearing smoke, looking for some sign as to the outcome of the battle. Was the American flag still flying? His wartime experience inspired Key to write a poem, which was later set to music and became America’s national anthem. This book tells the story of the inspiration behind our national anthem, which helped transform the flag into a...

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.