Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)

A surfer heads out at Coldingham Bay an inlet in the North Sea on February 15, 2012 in Coldingham, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

The Dora the Explorer balloon moves through Times Square during the Macy's Thanksgiving Day parade Thursday, November 23, 2006 in New York. (Photo by Frank Franklin II/AP Photo)

Cheering The News of Germany's Surrender New Yorkers Gather around a youth wearing a mask of Adolf Hitler to cheer the news of the Surrender of Germany on May 7. The Crowd is gathered in times Square, New York. May 08, 1945. (Photo by New York Post/Photo Archives, LLC via Getty Images)

Wrestler Kairi Hojo jumps at her opponent Mieko satomura during their Stardom female professional wrestling show at Korakuen Hall in Tokyo, Japan, July 26, 2015. Professional women's wrestling in Japan means body slams, sweat, and garish costumes. But Japanese rules on hierarchy also come into play, with a culture of deference to veteran fighters. The brutal reality of the ring is masked by a strong fantasy element that feeds its popularity with fans, most of them men. (Photo by Thomas Peter/Reuters)

Spanish soldiers of the 7th Airborne Light Infantry Brigade “Galicia” fire a howitzer Light Gun L118 during maneuvers with other units in preparation to NATO's Very High Readiness Joint Task Force (VJTF) in Zaragoza, Spain, April 19, 2016. (Photo by Javier Cebollada/EPA)

An armed man herds his cattle close to the village of Nimini in northern South Sudan, February 8, 2017. In the chaos of South Sudan's civil war, it took three years for Nyagonga Machul to find her lost children. Machul had traveled from her village to the capital when President Salva Kiir, an ethnic Dinka, fired his deputy Riek Machar, a Nuer, in 2013. (Photo by Siegfried Modola/Reuters)

Residents with faces covered in ash ride on a motorcycle as Mount Sinabung volcano erupts, in Sukandebi village in Karo Regency, Indonesia's North Sumatra province, Indonesia June 13, 2015, in this photo taken by Antara Foto. (Photo by Rony Muharrman/Reuters/Antara Foto)