Performers Roni, Liv and Becky behind the scenes at Great Yarmouth Hippodrome Circus, England. (Photo by Nick Warner/The Guardian)

Members of the Mayossa folk dance group pour water on a young woman in Kiskunmajsa, Hungary on April 2, 2018. According to an old Hungarian tradition, celebrated for several hundred years, young men pour water on young women, who in exchange present their sprinklers with beautifully colored eggs on Easter Monday. (Photo by Sandor Ujvari/EPA/EFE/Rex Features/Shutterstock)

Charlotte Caslick of Australia is tackled by Jasmine Joyce of Wales during the Rugby Sevens Women's Pool B match between Australia and Wales on day nine of the Gold Coast 2018 Commonwealth Games at Robina Stadium on April 13, 2018 on the Gold Coast, Australia. (Photo by Dan Mullan/Getty Images)

Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

Senior Buddhist monk Lobsang Tayang sits outside the Amarbayasgalant Monastery in the Baruunburen district, Selenge province, Mongolia, April 26, 2018. (Photo by Thomas Peter/Reuters)

A woman from the Hui Muslim community carries food that will be eaten by her and others to break their fast during the holy fasting month of Ramadan at the Nanxiapo Mosque on June 8, 2018 in Beijing, China. (Photo by Kevin Frayer/Getty Images)

German Nazi leader Adolf Hitler (1889 - 1945) enjoys a quiet picnic between meetings, circa 1933. Picture 196 of a series of collectable images published in Germany during the Nazi period, entitled “Deutschland Erwacht” (Germany Awakes). (Photo by Heinrich Hoffmann/Hulton Archive/Getty Images)

Two brown bears bathe in their enclosure at the Wildpark Poing in Poing, Germany, Wednesday, August 8, 2018. (Photo by Lino Mirgeler/Deutsche Presse-Agentur via AP Photo)