This website gave me cancer in so many different ways. Most times, it's just plain wrong. It's teaching style is outdated and quite terrible for non-visual learners. If you don't know something, instead of helping you, it makes you answer the same type of question two more times until you can go back to where your effort doesn't count, and probably fail again. And teachers all around the world still use it! In short, i'd rather have smoked all my life then sentence kids to do this.