David Armentrout Libros

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

A simple biography of the naturalist who founded the Sierra Club and was influential in establishing the national park system.

Follows the life and career of the French scientist who proved the existence of germs and their connection with diseases.

Define planos inclinados, explica sus funciones, y sugiere experimentos sencillos para demostrar cómo funcionan.