Chinese President Xi Jinping said the "well-measured use of natural resources is the key to ecological conservation," during the opening ceremony of the International Horticultural Exhibition in 2019.

The sentence was a quote from "Comprehensive Mirror in Aid of Governance," a pioneering reference work in Chinese historiography by Sima Guang (1019-1086) of the Northern Song Dynasty (960-1127).

The quotation shows China's ancient wisdom regarding the balance between nature and humans. The idea of the well-measured use of natural resources has taken on new meaning in China today.