Gao Dun, I've listened to all the classes in Dongao. The first time I listened to Zhang Zhifeng accountant, I felt that I didn't learn anything after listening for half an hour, so I gave up Dongao directly. Both Chinese and Gao Dun's classes were good, but in the end I chose Gao Dun's. The reason is that there is interaction in Gao Dun's class, and students often ask the same questions as mine.