Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

“Left behind” children Luo Hongni, 11 (L) and brother Luo Gan,10, carry flowers to be used as feed while doing chores in the fields on December 18, 2016 in Anshun, China. Like millions of Chinese children, the four Luo siblings are being raised by their grandparents in rural China as their parents left to find work in urban areas. (Photo by Kevin Frayer/Getty Images)

This photo taken on May 20, 2020 shows elementary school students wearing wings to maintain social distancing amid concerns of the COVID-19 coronavirus, in a classroom in Taiyuan in China's northern Shanxi province. (Photo by AFP Photo/China Stringer Network)

A cat receives acupuncture treatment in Shanghai, China on August 21, 2017. Traditional practitioners believe acupuncture of the body can stimulate blood circulation to promote healing and relieve some aches and pains. (Photo by Aly Song/Reuters)

A security personnel keeps watch before the second plenary session of the National People's Congress (NPC) at the Great Hall of the People in Beijing, China on March 8, 2022. (Photo by Carlos Garcia Rawlins/Reuters)

An armed police officer attends an explosive ordnance disposal training on April 12, 2022 in Nanning, Guangxi Zhuang Autonomous Region of China. (Photo by Yu Haiyang/VCG via Getty Images)

Train attendants attend an etiquette trainning as the May Day holiday approaches on April 26, 2022 in Chongqing, China. (Photo by Su Zhigang/VCG via Getty Images)

A participant wearing his cosplay featuring a character from an animation gets his government contact tracing QR code in the “LeaveHomeSafe” COVID-19 mobile app scanned at Ani-Com and Games exhibition in Hong Kong, Friday, July 29, 2022. (Photo by Kin Cheung/AP Photo)