Book excerpt: A quick-in, quick-out Earth Science study guide that includes subject review chapters and practice questions throughout CliffsNotes Earth Science Quick Review, 2nd Edition, provides a clear, concise, easy-to-use review of earth science basics. Perfect for middle school and high school students, as well as for anyone wanting to brush up on their knowledge of how the earth's systems function.Whether you're new to minerals and rocks, or motions of the earth, moon, and sun, or just wanting to refresh your understanding of the subject, this guide can help. Aligned to NGSS, it includes topics such as plate tectonics and mountain formation, weathering and erosion, and measurements and models of the earth. The target audience is substantial: Approximately 49% of the nation's 8th graders take an earth science course, and slightly over 17% of high school students take the course before graduating.