A participant races in the Brompton World Championship in Bern, Switzerland October 21, 2018. (Photo by Stefan Wermuth/Reuters)

Birds sit on the back of a zebra in the Nairobi National Park, near Nairobi, Kenya, November 21, 2018. (Photo by Baz Ratner/Reuters)

A boy jumps over a puddle of water on the outskirts of Havana, Cuba March 21, 2016. (Photo by Ueslei Marcelino/Reuters)

A runner in fancy dress participates in the Virgin London Marathon 2013 on April 21, 2013 in London, England. (Photo by Tom Dulat/Getty Images)

Dancers perform “El torito”, during a celebration honoring Saint Thomas, the patron saint of Chichicastenango, Guatemala, Saturday, December 21, 2019. The Feast of Saint Thomas draws international tourists with its colorful pageantry, but at its heart is a religious celebration melding Catholic and indigenous traditions that culminates on Dec. 21. (Photo by Moises Castillo/AP Photo)

A South Sudanese People Liberation Army (SPLA) soldier patrols the streets in Malakal on January 21, 2014. (Photo by Harrison Ngethi/AFP Photo)

A woman walks inside a building in downtown Havana, Cuba April 21, 2016. (Photo by Alexandre Meneghini/Reuters)

A mahout bathes his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India May 21, 2017. (Photo by Amit Dave/Reuters)