This informational book on marijuana is part of a series of three interactive books on tobacco, alcohol, and marijuana; three informational books containing parallel content; and three teacher guides designed to give students in grades five through eight practice in using the information and skills presented in the books. The goal of this book and the accompanying interactive book and teacher guide is to prevent marijuana use by preadolescents. This book provides information about the effect of marijuana on the body and about health problems that may result from using this drug. It describes what a drug is, considers prescription and other drugs, explains what marijuana is, and looks at illegal drugs and their use. Health problems resulting from marijuana use are described and examples are given of how some young people begin to use marijuana. It notes that most teenagers do not use marijuana and reminds students that the decision to use marijuana is their choice to make. (NB)