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What do a shark, a seahorse, and a ray have in common? They're all fish! Learn about the characteristics that all fish share.

Young readers will survey the discovery of the American colonies through the eyes of explorers, soldiers, and civilians.

Diccionario para escolares que incluye los significados de las palabras, modelo de verbos, palabras de uso científico y tecnológico, ejemplos de uso y cultura, regionalismos latinoamericanos, etc.

Explains, in simple terms, the reasons for skin color, how it is determined by heredity, and how various environmental factors affect it.