Gr 3-6-- For those who have ever wondered how fish sleep, why a hologram appears three-dimensional, or how a sponge can hold water when it is full of holes, this is the book. These and many other questions are answered in this fascinating science miscellanea. The question-and-answer format, appealing color photographs, clearly-written text, and interesting topics are sure to appeal to browsers. A good index helps to locate specific information. Although the answers are relatively short, they provide basic information about a variety of topics. A quality selection. --Eunice Weech, M. L. King Elementary School, Urbana, Ill.