A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

A woman walks up the steps decorated ahead of the Chinese New Year festival in Beijing, China, Thursday, January 12, 2017. The Chinese Lunar New Year is the most important holiday for Chinese and hundreds of millions are expected to return to their hometown to spend the new year with their family and relatives. (Photo by Ng Han Guan/AP Photo)

A man makes traditional candy “Matang” in preparation for the upcoming Chinese Lunar New Year in Yuqing County, Zunyi, Guizhou Province, China, January 18, 2016. (Photo by Reuters/China Daily)

People walk during a polluted day in Shenyang, Liaoning province, March 31, 2016. (Photo by Reuters/Stringer)

Police officers display their AI-powered smart glasses in Luoyang, Henan province, China on April 4, 2018. (Photo by Reuters/China Stringer Network)

Video bloggers stream live broadcast of an event to celebrate the fourth birthday of the world's only giant panda triplets, Meng Meng, Shuai Shuai and Ku Ku, at Chimelong Safari Park in Guangzhou, China July 29, 2018. (Photo by Bobby Yip/Reuters)

A father crosses a road with his twin daughters in Shanghai, China September 28, 2018. (Photo by Aly Song/Reuters)

An army dog stands up as retiring soldiers salute their guard post before retirement in Suqian, Jiangsu province, China on November 29, 2017. (Photo by Reuters/China Stringer Network)