I bought the CD, along with a driving textbook. Some chapters of the book you have to look at, of course, to understand certain connections. The actual and effective in my view of the theoretical preparation. But the audit was to work with the CD. The selection of the proposed class is easy, as well as the entire operation. You can answer the questionnaires at the beginning but the thematic questionnaires are better, since all the other questions of a theme complex. With a few hours of effort and a good feeling, it has then also straight away with the Theoret. Fold test. In my view, the CD is highly recommended - you also good luck.