A man wearing a mask and dressed in a clown costume rides an electric tricycle while carrying a container in the shape of a rubber duck amid heavy smog in Beijing, China, December 29, 2015. (Photo by Jason Lee/Reuters)

A woman scales fish by the side of a lake as she prepares for the upcoming Chinese Lunar New Year in Suqian, Jiangsu province, China, January 27, 2016. (Photo by Reuters/China Daily)

Paramilitary policemen carry tyres as they take part in a training session in Zhangye, Gansu Province, China, March 1, 2016. (Photo by Reuters/Stringer)

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)

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)