1. The famous saying about learning 1, Yin Jian is not far away, in Xia Hou's world. -The Book of Songs Yadang, which was anonymous in the pre-Qin period.

I can't help but notice that it is summer, and I can't help but notice that it is cloudy. It means that the descendants of Yin and Shang dynasties should take the demise of Xia as a warning and learn from the lessons of their predecessors.

2, the past is not forgotten, the teacher of the future. -The former phase "Warring States Policy Zhao Ceyi"

Remember the past and never forget the future.

3. Those who have been slapped will get a break, and those who have experienced it will gain wisdom. -Song Anonymous "Five Dynasties Han History Pinghua Han History"

After a setback, you learned your lesson; After one thing, you gain a point of wisdom.

4. Taking the past as a mirror, we can know the rise and fall. Take people as a mirror, you can know the gains and losses. -Tang Wujing, "Zhenguan politician Ren Xian"

Taking history as a mirror, we can know the rise and fall of dynasties; Only by taking people as mirrors can we understand the gains and losses.

5, future generations are sad and do not learn, but also make future generations sad and do not learn. -A Fang Gong Fu by Mutu in Tang Dynasty

If future generations only regret and don't learn lessons, they will be pitied by future generations.