Bests & Worsts Reviews from Amazon

I have been studying Spanish for 7+ years and used this book as a text book in a college course that focused on the verb conjugations and tenses. We did about 90% of the exercises in the book. It's very thorough with the material that it covers, but the answers in the back are full of so many mistakes that the book almost isn't worth it. It was frustrating for us students to use the book and check our answers only to find mistakes. Eventually our professor stopped using the book.