1. Isn’t it true that one should learn from time to time and practice it?

2. Be sensitive and eager to learn, and not ashamed to ask questions.

3. If you review the past and learn the new, you can become a teacher.

4. If you learn without thinking, you will be in vain; if you think without learning, you will be in danger.

5. When three of us travel together, we must be our teacher.

6. To know something is to know it, and to know something is to know something.