By Caren Weiner Campbell
February 12, 2000 at 05:00 AM EST

Ever wonder what’s really going on under your car’s hood, or inside the New York Stock Exchange, or in your toilet tank? This marvelously clear reference repository will clue you in. The aptly named Marshall Brain, a former North Carolina State University teacher, applies his gray matter to subjects ranging from cancer to marshmallows, and answers such reader queries as ”How do Sea Monkeys work?” or ”What do they put in hot dogs?” On second thought, maybe you don’t want to know….