Introduction to the spread of Western learning to the East: In the 16th century, European Christian missionaries came to the east, and there was a climax of cultural exchanges between China and the West. Missionaries such as Italian Matteo Ricci and German Tang Ruowang spread natural science knowledge to China, learned from each other with Chinese scholars Xu Guangqi, Li Zhizao and others, translated a number of Western scientific works, and manufactured scientific research instruments such as telescopes, reflecting advanced Western science. The impact of technology on China. Shown here is the scene in 1630 when Xu Guangqi and Li Zhizao, the supervisors of the Ming Dynasty Calendar Bureau, together with the Italian missionary Long Huamin and the German missionary Tang Ruowang, discussed Calendar at the Dongbianmen Observatory in Beijing.