A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

Tsetse, six-year-old daughter of Dukha herder Erdenebat Chuluu, sits among her family's reindeer in a forest near the village of Tsagaannuur, Khovsgol aimag, Mongolia, April 21, 2018. Nyamaa is an ethnic Darkhad, herders of northern Mongolia who have historically inhabited the steppe that borders the Taiga forests. (Photo by Thomas Peter/Reuters)

A girl looks out of a car at a checkpoint set up by Venezuelan security forces in Taguanes, Venezuela, February 21, 2019. (Photo by Andres Martinez Casares/Reuters)

A woman walks at the Boulevard of the River the eve of the International Women's Day, in Cali, Colombia, 07 March 2019. (Photo by Ernesto Guzman Jr./EPA/EFE)

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)

A man dressed as the Sesame Street character Big Bird sits on a bench waiting to take pictures with people walking through Central Park in New York U.S., November 14, 2016. (Photo by Shannon Stapleton/Reuters)

A woman paints the floor of a pond as her child pulls at her saree in Delhi, India November 23, 2016. (Photo by Cathal McNaughton/Reuters)

A group of people wearing Santa Claus hats and swimming suits participate in the 13th charity Great Santa Claus Run in downtown Budapest, Hungary, Sunday, December 11, 2016. (Photo by Balazs Mohai/MTI via AP Photo)