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

A petitioner with her grievances written on her clothes walks along a street in Beijing Tuesday, December 22, 2015. After months behind bars, Pu Zhiqiang, one of China's most prominent human rights lawyers, left a detention center Tuesday after receiving a suspended prison sentence in a case involving online comments critical of the ruling Communist Party. (Photo by Ng Han Guan/AP Photo)

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)

In this photo released by Xhinhua News Agency, a rescuer evacuates residents near the site of a chemical plant blast in Zhangzhou, southeast China's Fujian Province Tuesday, April 7, 2015. Six people have been hospitalized and hundreds of firefighters deployed to battle a blaze sparked by an explosion at Goure PX Plant that produces the toxic chemical paraxylene, officials said Tuesday. (Photo by Wei Peiquan/AP Photo/Xinhua)

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)