Papermaking appeared in the Western Han Dynasty and was improved by Cai Lun in the Eastern Han Dynasty. It is one of the four great inventions in ancient China.

(2) Zu Chongzhi in the history of world mathematics for the first time to calculate the value of pi to seven decimal places, nearly one thousand years ahead of the world.

Zhao Zhouqiao, designed and built by Li Chun, an outstanding craftsman in Sui Dynasty, is the oldest stone arch bridge in the world.

④ Printing includes block printing and movable type printing. Woodblock printing was invented in the Tang Dynasty, and movable type printing was invented in Bi Sheng in the Song Dynasty, about 400 years earlier than in Europe.

⑤ The Riverside Scene at Qingming Festival by Zhang Zeduan, a painter of the Northern Song Dynasty, depicts the scenery and prosperity of Yan 'an, which is an immortal work in the art history of China.