A. Once you know, you should use what you know to guide practice. Look at the result and verify whether what is known can achieve the goal. If success cannot be verified, find out all the reasons, make adjustments, continue with new practices, keep making adjustments and never give up. The word "give up" should not even be thought of until the goal is achieved. B. Only those who have achieved it truly know. If one truly knows, it must be verified through practice. Those who fail to achieve or...