Be sensitive to things and be careful what you say.

3, learning without thinking is useless, thinking without learning is dangerous.

People who don't believe don't know what they can do.

5. Speak slowly and act quickly.

6, Germany is not alone, there must be neighbors.

7, review the old and learn the new

8, a threesome, there must be my teacher.

9. Learn from time to time, not to mention?

10, knowing means knowing, not knowing means not knowing, just knowing.