1. Question, rather than question, "A real singer can sing the silence in people's hearts." —— Chai Jing

2. Those who have no doubts in reading must learn to have doubts, and those who have doubts must have no doubts. This is the only way to make progress. ——Zhu Xi

3. People who don’t ask will always be together with ignorance. ——East Africa

4. You cannot see the truth without doubt. ——Li Siguang

5. If your ears have no bottom, you can hear from morning to night. ——Africa