What Happened to the Dinosaurs?

The newest Let's-Read-and-Find-Out Book demonstrates the strengths of this dependable series: an understandable question and clear exposition of the answers that never fail to help readers to think like scientists throughout. Series originator Branley carefully lays out a number of scientific theories that answer the question posed in the title, giving the most space to theories developed after the discovery of large amounts of soot and iridium in rock layers. Simont's well-placed drawings and watercolors carefully amplify and expand the text. Ages 10-up. (Sept.)