Couples take part in a competition during a mass wedding of 64 doctoral student couples at Harbin Institute of Technology, a university in Harbin, Heilongjiang province, China, June 4, 2017. (Photo by Reuters/Stringer)

Tourists crowd a water park in Wuhan city, central China's Hubei province on July 15, 2017. Days of heat wave drove many citizens to the water park for fun and coolness. Nanchang has become the new four “furnace cities” in China according to a ranking of the hottest cities released by the China Meteorological Administration on July 9. (Photo by Imaginechina/Rex Features/Shutterstock)

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)

Women take a selfie next to a police officer as they take part in New Year's Eve celebrations in the Bund, in Shanghai, China December 31, 2016. (Photo by Aly Song/Reuters)

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)

A Chinese tourist wears protective gloves as she holds a baby Siberian tiger as they pose for pictures at the Heilongjiang Siberian Tiger Park on August 16, 2017 in Harbin, northern China. The center is one of two Siberian tiger parks in the Chinese province of Heilongjiang, about 500 kilometers (300 miles) from the border with Russia. It is considered the world's largest for breeding the Siberian, or Amur, tiger which is listed as endangered by the World Wildlife Federation. (Photo by Kevin Frayer/Getty Images)

A man performs a split as he practices Kung Fu at Beihai Park in Beijing, China August 20, 2017. (Photo by Reuters/China Stringer Network)

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)