I finished the last two courses with Brother Bing last year. I think I still have to learn by myself. Not everyone can be so responsible. I took the exam four times before and took many detours. I don't know how to pass the exam myself. However, studying in Bingo let me know the gap, and 15 will basically have a bottom. This is the different effects brought by different teachers. It may not be suitable for you, but the result will not be bad if it is suitable.