Portuguese runner Adriele Silva gestures during the Great Wall Marathon at the Huangyaguan section of the Great Wall of China, in Jixian of Tianjin, China May 19, 2018. (Photo by Jason Lee/Reuters)

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)

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)

Hospitality staff are reflected in a puddle of water as they prepare to pose for photograph in front of a giant basket decorated with replicas of flowers and fruits on display on Tiananmen Square during the opening ceremony of the 19th Party Congress in Beijing, Wednesday, October 18, 2017. Chinese President Xi Jinping on Wednesday urged a reinvigorated Communist Party to take on a more forceful role in society and economic development to better address “grim” challenges facing the country as he opened a twice-a-decade national congress. (Photo by Andy Wong/AP Photo)

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)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)

Aerial view of CRH bullet trains setting out ahead of Spring Festival travel rush on January 31, 2018 in Hefei, Anhui Province of China. About 2.98 billion trips will be made during the 40-day Spring Festival travel rush. China will take multiple measures to ensure a smooth Spring Festival travel rush. (Photo by VCG/VCG via Getty Images)