The key is to see if you have time. This requires systematic review, and at least two or three hours of study time every day according to the introduction of friends you have met, so you must devote yourself wholeheartedly. We will prepare the teaching materials when time is guaranteed. Now we are using four textbooks of 20 12. After reading and understanding, we will do problems, practice doing problems, and finally read books, and then make a systematic summary. Read guides and laws and regulations if you don't understand them. That's all I can do. Time is guaranteed. After the above process, I can understand most of the knowledge. As for the degree of mastery, it depends on my personal practice. I can join some learning exchange groups, which is better! @