Todo es un ciclo

Examines the nature of inclined planes and wedges, how they can reduce the amount of force necessary to perform work, and ways in which they are used.

Got a fan of snakes, lizards, and turtles? Dig into this beginner's guide to reptiles from Cathryn and John Sill, creators of the award-winning About... series. Author and educator Cathryn Sill explains in simple language the basic characteristics that all reptiles share, while offering a look at many of the animals that fall into this diverse category, including ever-popular lizards, snakes, and turtles. The beautifully detailed paintings of noted wildlife illustrator John Sill depict reptiles in their habitats and highlight their unique aspects. An afterword provides more detail on each...

Venerado y vilipendiado a un tiempo, Lobachevski se cierne imponente sobre la matemática del siglo XIX. Al igual que sucede a la mayoría de los mitos, el Lobachevski real está oculto por capas de negligencia y desconocimiento. Su fantástica obra, argumentaban muchos, no era otra cosa que herejía matemática, una senda falsa. Lobachevski es una personalidad abrumadora, un soñador empedernido, un hacedor de mundos imposibles pero reales. Lobachevski es, para muchos, una persona desconocida. Este libro cuenta la historia de un hombre sencillo, pero sagaz, obstinado y profundo desde el...

Modeled after the adult version of Oracional bilingüe: A Prayer Book for Spanish-English Communities, this volume for children encourages prayer across national, cultural, and linguistic borders. Oracional bilingüe para niños provides Spanish and English texts of the most loved and commonly used prayers in large, readable type and in an easy-to-follow, facing-page, parallel presentation. The English text appears on the left page, with the Spanish text directly across from it on the right. In addition, illustrations by well-known artist Gertrud Mueller Nelson complement each page and add to ...