Students hold their weapons before the swearing in ceremony for the military students, in Bucharest, Romania, Wednesday, October 25, 2017. The Romanian Army is proudly celebrating their Army Day and marking 100-years since the landmark battle of Marasesti, a key World War I battle in 1917 when Romanian and Russian soldiers defeated German troops, halting a German offensive. (Photo by Vadim Ghirda/AP Photo)

An officer reviews members of the honor guard as they line up before a welcoming ceremony for visiting Mozambique's President Filipe Jacinto Nyusi at the Great Hall of the People in Beijing, Wednesday, May 18, 2016. (Photo by Mark Schiefelbein/AP Photo)

Egyptian bootblacks cleaning a European's shoes in Cairo. (Photo by Hulton Archive/Getty Images). Circa 1870

A Syrian migrant family enters Hungary at the border with Serbia near Roszke, Hungary August 28, 2015. As Europe struggles with its worst migrant crisis since World War II, Hungary has become, like Italy and Greece, a “frontline” state. So far this year, police say around 141,500 migrants have been intercepted crossing into Hungary, mostly from neighbouring Serbia. (Photo by Bernadett Szabo/Reuters)

Marco Antonio Eguchi of Brazil gets bucked off of Bottoms Up in the first round of the PBR Frontier Communications Iron Cowboy at AT& T Stadium on February 18, 2017 in Arlington, Texas. (Photo by Tom Pennington/Getty Images)

The worlds largest cruise ship, the 361 metres long, Harmony of the Seas, arrives in port for her mayden voyage, in Southampton, Britain May 17, 2016. (Photo by Peter Nicholls/Reuters)

A dog is seen at the entrance of a house in the flooded residential area of Villeneuve-Saint-Georges, near Paris, France January 26, 2018. The Paris region has been deeply affected by the floods that hit the country over the past week, but in Paris, it was business as usual. (Photo by Christian Hartmann/Reuters)

People ride a bus as they travel in Yangon, Myanmar January 14, 2017. Picture taken January 14, 2017. (Photo by Soe Zeya Tun/Reuters)