A couple covered in mud wait for it to dry at the Salt-works lakes near the Black Sea town of Burgas in Bulgaria on July 25, 2019. Thousands of tourists visit the red salt lakes for mud baths, which are believed to help the healing of muscular disorders and rheumatism. (Photo by Nikolay Doychinov/AFP Photo)

This picture taken on June 25, 2019 shows couples wait for their turn for their pre-wedding photo shoot at the Love Story in Rome Studio in Beijing. Increasingly elaborate pre-wedding photos are a booming industry in China, as young couples spend time and cash lining up glamorous photo shoots to display on their big day. (Photo by Fred Dufour/AFP Photo)

Danielle Collins of the US reacts to a point in the first set while playing Caroline Wozniacki of Denmark during Round Two Women's Singles tennis match of the 2019 US Open at the USTA Billie Jean King National Tennis Center in New York on August 29, 2019. (Photo by Robert Deutsch/USA TODAY Sports)

A zoo keeper carries a pelican to move it to its winter enclosure at Dvur Kralove Zoo in Dvur Kralove nad Labem, Czech Republic on November 5, 2019. (Photo by David W. Cerny/Reuters)

Protesters run for cover after riot police fired tear gas towards the bridge they were climbing down to the road below, to escape from Hong Kong Polytechnic University campus and from police, in Hung Hom district in Hong Kong on November 18, 2019. Dozens of Hong Kong protesters escaped a besieged university campus on November 18 by lowering themselves on a rope from a footbridge to a highway, AFP video showed. Once on the road they were seen being picked up by waiting motorcyclists. (Photo by Anthony Wallace/AFP Photo)

A man wearing a traditional Russian costume holds a goose after a traditional goose fight during celebrations of Maslenitsa, also known as Pancake Week, which is a pagan holiday marking the end of winter, in Suzdal, Russia on February 29, 2020. (Photo by Maxim Shemetov/Reuters)

A female tourist wears a protective face mask on the street, following an outbreak of the coronavirus disease (COVID-19), in Tokyo, Japan on March 10, 2020. (Photo by Hannibal Hanschke/Reuters)

A police officer chases shoppers to clear the streets of the Red Light market on the first day of lockdown to stop the spread of the coronavirus disease (COVID-19) in Monrovia, Liberia on April 11, 2020. (Photo by Derick Snyder/Reuters)