The Princeton Review ACT book is a comprehensive study guide designed to help students prepare for the ACT exam. It includes practice tests, strategies for each section of the exam, and tips for improving test-taking skills. The book also includes detailed explanations of the answers to the practice questions, so students can learn from their mistakes and improve their scores. With thorough coverage of the material tested on the ACT, the Princeton Review ACT book is a valuable resource for students looking to achieve their best possible score on the exam.