This is the fourth of Asimov's ABC books and like the others it suffers from the inaptness of the concept itself. With alphabetical rather than logical order dictating the arrangement, such incongruous pairings as bark beetle and biome, carbon monoxide and conservation, game refuge and garbage, are inevitable. So too are such arcane x's as xerophyle and xylophage following the self-evident weather (defined as "the changing conditions of the air. . . . It can be windy, rainy, snowy, foggy, cold or hot.") As for the paragraphs' contents, what is a child to make of the announcement that "A is for additive, a material added for improvement. . . . Sometimes additives can harm the body"? Then there is the statement on detergent, that "if too much gets into lakes and rivers, it can change the balance of nature," with no hint of how this happens, and three entries later a paragraph on eutrophication, with no mention of detergent. The book is printed on recycled paper and we can assume too that it's compiled from scraps of recycled data out of Dr. A's copious files.