An instructor (C) adjusts the posture of students of flight attendant major during a training session at Anhui Foreign Languages University, in Hefei, Anhui province, China, May 25, 2015. (Photo by Reuters/China Daily)

Employees wear "No-Face" masks during working hours at a service company in Handan, Hebei Province of China. As a service company, staff must smile to customers every day. On “No-Face Day”, staff wore masks to hide their facial expressions and allow them to relax. No-Face is a character in the 2001 animated movie “Spirited Away”, a silent masked creature who has no facial expressions.

People fight for the ball as they take part in a mud football match during a festival for celebrating harvest in a village in Jinhua, Zhejiang Province, China September 24, 2017. (Photo by Reuters/China Stringer Network)

People dance in a park on a foggy day in Huai'an, Jiangsu province, China October 10, 2017. (Photo by Reuters/China Stringer Network)

Bicycles of various bike-sharing services are seen at an urban village in smog during a polluted day in Shanghai, 2017. Rapid expansion of shared bicycle companies across China has led to massive piles of abandoned bikes as supply outstrips demand. (Photo by Aly Song/Reuters)

Cha Huilan, a 40-year old Lisu woman, and her daughter leave Lazimi village with a zipline across the Nu River in Nujiang Lisu Autonomous Prefecture in Yunnan province, China, March 24, 2018. Chinese mountain villagers, cut off from shops and churches by a raging river, use a zipline to cross its violent rapids and jagged rocks. (Photo by Aly Song/Reuters)

July gestures next to her boyfriend Jason Schaller while they are suspended from hooks pierced through their skins by professional body artist Wei Yilaien at a bar in Shanghai, China September 16, 2018. “I like being unique and I don't like doing things that many people are aware of and would accept”, said Wei, 24, who staged the show of extreme body piercing in China's normally buttoned down financial capital. (Photo by Aly Song/Reuters)

A participant, surrounded by red chilli peppers, takes part in a chilli-eating competition at a hot spring in Yichun, Jiangxi province, China on December 9, 2018. (Photo by Chen Fei/China News Service via Reuters)