Prince Philip, Duke of Edinburgh practicing his bicycle polo technique, Windsor Great Park, Berkshire, 1964. (Photo by Norman Potter/Daily Express/Hulton Archive/Getty Images)

Two Czech Gripen fighter planes demonstrate a flight interception of a Belgian air force transport plane over the Czech Republic, as part of NATO drills on September 12, 2018. (Photo by Francois Lenoir/Reuters)

In this August 24, 2018 photo, Changlair Aristide pauses for a portrait, wearing his protective clothing, including an old U.N. peacekeeper's jacket he found in the trash, before scavenging the Truitier landfill in the Cite Soleil slum of Port-au-Prince, Haiti. Before 2004, Aristide recalled having enough money to splurge on shoes, T-shirts and pants, but this year he could not buy his kids anything new for the school year. “Life is like that, up and down”, Aristide said. “They'll go to school anyway, even if I have to sell my pig. I love them”. (Photo by Dieu Nalio Chery/AP Photo)

Sasha Muir and Margaret Davidson sit in a car as some of the 30 barbary macaques, known as the Middle Hill Troop after living between the top of Gibraltar rock and the town, show what happens when motorists forget to lock their luggage compartments, as Scotland’s only monkey drive-through section opens at Blair Drummond safari park in Stirling, Scotland on October 8, 2015. (Photo by Andrew Milligan/PA Wire)

Ivorian police officers of the Anti-Riot Brigade (BAE) contain the crowd during a performance by French rapper Okou Armand Gnakouri known as Kaaris during the Festival of Urban Music of Anoumabo (Femua) in Abidjan on April 28, 2019. The performance of French-Ivorian rapper Kaaris at the Festival of Urban Music of Anoumabo (Femua) in Abidjan escalated into violence after a crowd surge, causing some minor injuries, according to an AFP journalist at the concert. (Photo by Sia Kambou/AFP Photo)

A girl in an angel costume walks with her family past vegetable vendors in Havana, Cuba, Wednesday, April 10, 2019. (Photo by Ramon Espinosa/AP Photo)

Palestinian man Mohammed al-Hoor, 23, demonstrates his street workout skills in Nuseirat refugee camp, in the central Gaza Strip on May 2, 2017. (Photo by Mohammed Salem/Reuters)

Soldier boys at Fort Dix, N.J., learn something about guns during their working hours, as they show their girlfriends at a camp dance, December 13, 1940. In front row, playing with the coin amusement gun, from left: Pvt. Tom D'Amato of West Orange; Rose Sinkewicz, behind gun site, of Trenton; Julia Ivans of Trenton, and Pvt. Vernon Landers of Kearney. Back row: Pvts. William Sargent and William Corlies of Philadelphia. (Photo by AP Photo)