The central idea of the article "Ask if you don't understand" is: learn, learn, ask if you don't understand. In order to understand the truth, it is worthwhile to be beaten.

This text is the first lesson in the first volume of the third grade of China People's Education Publishing House. It tells the story that Sun Yat-sen boldly asked the teacher in a private school, not afraid of being criticized, and finally got an answer from the teacher.