my roommate used this book to prep for the MCAT and she told me about it. I'm glad I bought it and used it for my studies. the questions were great to teach me the subtle differences between the concepts. I read all the explanations and these were invaluable to review and learn the material. The explanations are what separated this book from the others that I used. my roommate told me about it and I'm happy with it so I told other premeds about it. Great book.