Visitors view exhibits during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province, Jan. 16, 2020. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday. (Photos: Xinhua/Li An)

Visitors view exhibits during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province, Jan. 16, 2020. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday.

Photo taken on Jan. 16, 2020 shows an exhibit during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday.

Visitors view an exhibit during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province, Jan. 16, 2020. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday.

Visitors view an exhibit during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province, Jan. 16, 2020. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday.

Visitors view exhibits during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province, Jan. 16, 2020. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday.

Visitors view a board display during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province, Jan. 16, 2020. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday.

Visitors view exhibits during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province, Jan. 16, 2020. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday.

Visitors view exhibits during an exhibition of Emperor Qianlong in Zhengzhou, central China's Henan Province, Jan. 16, 2020. An exhibition showcasing cultural relics of Emperor Qianlong kicked off in Zhengzhou on Thursday.