Soldiers of China's People's Liberation Army (PLA) jump as part of their winter training in temperature of negative 26 degrees Celsius at China's border with Russia in Heihe, Heilongjiang province, December 14, 2015. (Photo by Reuters/Stringer)

Playboy Bunnies pose for a selfie at the premiere of “The Transporter Refueled” at Playboy Mansion in Los Angeles, California August 25, 2015. The movie opens in the U.S. on September 4. (Photo by Mario Anzuoni/Reuters)

A picture made available on 30 March 2016 shows members of the anti-terror squad of the local paramilitary force have a training in Suining, in southwest Sichuan province, China, 29 March 2016. (Photo by Zhong Min/EPA)

A Uyghur boy sits atop a horse as he has his picture taken outside the Id Kah Mosque before the Eid holiday on July 28, 2014 in old Kashgar, Xinjiang Province, China. Nearly 100 people have been killed in unrest in the restive Xinjiang Province in the last week in what authorities say is terrorism but advocacy groups claim is a result of a government crackdown to silence opposition to its policies. China's Muslim Uyghur ethnic group faces cultural and religious restrictions by the Chinese government. Beijing says it is investing heavily in the Xinjiang region but Uyghurs are increasingly dissatisfied with the influx of Han Chinese and uneven economic development. (Photo by Kevin Frayer/Getty Images)

A relative of a victim of the Ukraine International Airlines PS 752 plane that crashed after taking off from Tehran's Imam Khomeini airport reacts at Boryspil International Airport, outside Kiev, Ukraine on January 8, 2020. (Photo by Serhii Nuzhnenko/Reuters)

People wear face masks to protect against the coronavirus as they walk across an intersection in Beijing, Friday, June 5, 2020. China on Friday reported five new confirmed coronavirus cases, all of them brought by Chinese citizens from outside the country. (Photo by Mark Schiefelbein/AP Photo)

A young woman smokes a cigarette straddled across a man's lap on Ladies' Day at Epsom, England on June 2, 2017. Ladies' Day is traditionally held on the first Friday of June, a multitude of ladies and gents head to Epsom Downs Racecourse to experience a day full of high octane racing, music, glamour and fashion. (Photo by Peter Dench/Getty Images Reportage)

Young women wearing facemasks and traditional costumes of Song dynasty and Tang dynasty are seated on a bench in a park next to the East Lake in Wuhan, in China’s central Hubei province on May 17, 2020. The Guardian picture desk has chosen on December 17, 2020, the AFP photojournalist Hector Retamal as “Agency Photographer of the Year 2020” for his coverage of the novel coronavirus Covid-19 pandemic in Wuhan, China. (Photo by Hector Retamal/AFP Photo)