② Emperor Wen of Sui Dynasty, Emperor Zhen Guan of Sui Dynasty (Emperor Taizong) and Shi Sheng of Kaiyuan (Emperor Xuanzong of Tang Dynasty).
(3) 1. National unification
2. Cultural prosperity, integration of the three religions, imperial examination policy, and cultural exchanges with neighboring countries.
3. The enlightened policy of the rulers
(4) 1. Maintaining national unity is the foundation of national prosperity.
2. To build a learning society, only when science and technology prosper can the country prosper.
3. Carry forward traditional culture and promote cultural prosperity and exchange.