This Spanish-language book is one in a series of four entertaining What Do You Know About? books, for very young children whose first language is Spanish. Attractive color illustrations and easy-to-follow text combine to present factual information that younger boys and girls will readily absorb and understand. ¿De qu© est¡n hechas las cosas?, which is Spanish for "What Are Things Made Of?," describes how familiar objects are made from minerals like iron or fashioned from wood or plastic or glass. Four pages presenting activities for children appear at the back of the book, followed by a two-page section for parents, with tips on explaining the subject in more detail.