Students attend a stewardess skill training for the upcoming 2017 entrance examination for art majors in colleges in Luoyang, central China's Henan Province, January 4, 2017. Along with how to stand, how to sit is also covered in these classes. (Photo by Li Bo/Xinhua/Barcroft Images)

Participants take pictures of themselves as others run past the Tiananmen gate during the Beijing Marathon in Beijing, China, September 17, 2016. (Photo by Damir Sagolj/Reuters)

Flames from a burning barricade lit by pro-democracy protesters is reflected in the windows of a passing bus as passengers watch on during a protest gathering in front of Mong Kok police station on September 22, 2019 in Hong Kong, China. Pro-democracy protesters have continued demonstrations across Hong Kong, calling for the city's Chief Executive Carrie Lam to immediately meet the rest of their demands, including an independent inquiry into police brutality, the retraction of the word “riot” to describe the rallies, and genuine universal suffrage, as the territory faces a leadership crisis. (Photo by Chris McGrath/Getty Images)

This photo taken on November 4, 2019 shows people taking part in a fish catching competition in a paddy field in Leishan county in China's southwestern Guizhou province, to celebrate the new year festival Miao people. (Photo by AFP Photo/China Stringer Network)

A fisherman with a close bond to cormorants uses the flock of birds to catch big fish in Li river in Guilin, China. The aquatic birds can be seen perching on a bamboo raft before swooping into the calm water to grasp hold of prey. (Photo by Julia Wimmerlin/Solnet News & Photo Agency)

A staff member of Yutian County poses for a video on marigold industry at an agricultural industrial park in Yutian County, northwest China's Xinjiang Uygur Autonomous Region, September 20, 2020. As one of the five counties in Hotan Prefecture that have not been lifted out of poverty, Yutian County is accelerating its steps to shake off poverty by planting marigold. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)

A woman poses for a photo in the tourist area surrounding Houhai Lake during Chinese National Day holidays in Beijing, China, October 2, 2020. China is celebrating its national day marking the 71st anniversary of the People's Republic of China and the Mid-autumn Festival for a week beginning on October 1st. (Photo by Thomas Peter/Reuters)

A migrant worker wearing face masks to help curb the spread of the coronavirus walks up to a pedestrian bridge in Beijing, Sunday, December 6, 2020. Provincial governments across China are placing orders for experimental, domestically made coronavirus vaccines, though health officials have yet to say how well they work or how they may reach the country's 1.4 billion people. (Photo by Andy Wong/AP Photo)