If you want to take the exam, it's good to listen to what your friends say. It's very reliable.
Education in Du Wen is really good. I taught myself for about three months before the exam, but I always couldn't grasp the key points because of too many knowledge points. Later, I signed up for an education class in Du Wen. The teacher is very experienced and will arrange knowledge points for us and plan time reasonably and freely. I really regret not signing up for class earlier.