Examples of modern practical knowledge are: Yuan Longping, the "father of hybrid rice", Edison invented electric light, Sima Qian wrote historical records, Feng Zikai sold sheep, Zhu Kezhen, a famous meteorologist, Shennong tasted a hundred herbs, Lu Ban invented giants and so on.

Practice: all human activities to actively transform nature and society. Out: produce. True knowledge: knowledge that conforms to objective reality and objective laws. That is, regular knowledge can be summarized through social practice.

A famous saying about practice makes true knowledge.

1, things in the world, the listener is not as detailed as those who see, and those who see are not as detailed as those who live. -Lu You (Song).

2. Practice is a great whistleblower, which exposes all deception and self-deception. -Chernyshevski (Russia).

3. A person can only know his own ability by applying it in practice. Little seneca.

4. All theoretical laws depend on practical laws; If there is only one practical rule, then they all depend on it. Fichte.