La antigua Roma (Ancient Rome)

Wind Power: A waving flag, blowing leaves, a kite soaring through the skyall are moved by wind power. Wind is also our fast-growing source of energy. Find out how wind forms and the different ways we may use it in the future.

In Bosques, carefully leveled text and vibrant, full-color photographs take beginning readers on a tour of a temperate forest. Readers learn about this important ecosystem and the variety of living things adapted to live there.

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...

A closer look at the stomach and how it works with the digestive system to give the body the nutrients it needs to stay healthy.

“Dino” Don Lessem brings readers face-to-face with various dinosaur species, detailing their habitats, way of life and how they became extinct. An acclaimed dinosaur expert, Don Lessem has written more than 30 children’s books, writes a popular dinosaur column in Highlights magazine, and was an adviser for Jurassic Park. Take a trip through dinosaur time to meet these horned dinosaurs face-to-face: Torosaurus had the biggest skull of any animal ever! Pentaceratops had five sharp horns on its head! Styracosaurus was as big as an ice cream truck! Plus, you'll get to know Centrosaurus,...