A reveller wearing a mask and a period costume takes part in the Venice Carnival on February 24, 2019 in Venice, Italy. The carnival in Venice takes place until March 5, 2019. (Photo by Alberto Pizzoli/AFP Photo)

In this photo taken with long time exposure, a woman wears a hat at Churchill Downs before the 145th running of the Kentucky Derby horse race Saturday, May 4, 2019, in Louisville, Ky. (Photo by Charlie Riedel/AP Photo)

The northern lights, or aurora borealis, illuminate the sky over Flakstad beach on Lofoten Islands in the Arctic Circle on September 5, 2017. (Photo by Jonathan Nackstrand/AFP Photo)

A woman wears a face mask in the part of the city near neighbourhoods known for burning coal for heating in Ulaanbaatar, Mongolia January 26, 2017. Not many people in Ulaanbaatar wear masks to protect themselves against pollution. (Photo by B. Rentsendorj/Reuters)

An Anti-Capitalist protestor from the Occupy LSX movement at St. Paul's Cathedral on February 22, 2012 in London, England. (Photo by Matthew Lloyd/Getty Images)

People at a Czech Stop look at a cloud of smoke rising from the explosion in West, Texas, April 17, 2013. (Photo by Andy Bartee via Dallas Morning News/MCT)

Three Japanese tourists had to abandon plans to drive to Stradbroke Island off the Queensland coast when their hire car became bogged in mangrove mud, on March 15, 2012 near Stradbroke Island, Australia. (Photo by Chris McCormack/Fairfax Media).

In this May 24, 2018 file photo, rain drops accumulate on a car's windshield as commuters wait at a red light in Havana, Cuba. (Photo by Desmond Boylan/AP Photo)