People who fled the violence from Islamic State-controlled northern Syrian town of al-Bab arrive in the rebel-held outskirts of the town, Syria February 3, 2017. (Photo by Khalil Ashawi/Reuters)

Freshmen in Zhengzhou Institute of Aeronautical Industry Management head bottles of mineral water for upright stand during military training on September 17, 2015 in Zhengzhou, Henan Province of China. More than 6,800 freshmen in the school are required to take part in the military training. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

People in traditional dance before competing in the 53rd Verdiales music contest in Malaga, southern Spain December 28, 2014. Verdiales is a form of traditional Flamenco music, which is common in the province of Malaga. Members of singing groups, known as “pandas”, wear traditional costumes decked with flowers and other accessories as they perform in the contest, which is held annually on December 28. (Photo by Jon Nazca/Reuters)

A girl walks down the runway during a class at a modelling academy in Caracas, Venezuela, on September 20, 2014. Venezuela's famed models and aspiring beauty queens are struggling to doll themselves up. In a country that glorifies voluptuous women and opulent beauty pageants, even basics like deodorant are now at times tricky to find as strict currency controls have led to a scarcity of dollars for imported goods. (Photo by Carlos Garcia Rawlins/Reuters)

In this photo taken Tuesday, October 14, 2014, skulls and bones are stacked at the Catacombs in Paris, France. The subterranean tunnels, stretching 2 kilometers (1.24 miles), cradle the bones of some 6 million Parisians from centuries past and once gave refuge to smugglers. The site used to close at 5 p.m., but is now staying open until 8 p.m. The change is mainly aimed at allowing more people to visit and reducing long lines, since it can only hold a limited number of people at a time and visits can't be reserved in advance. (Photo by Francois Mori/AP Photo)

Couples participate in the “Running of the Brides” race in a park in Bangkok November 29, 2014. Seventy-five husbands and wives-to-be wore their wedding dresses and running shoes and competed in an event for a combined prize worth 1 million Thai baht ($30,460). (Photo by Damir Sagolj/Reuters)

A participant, riding a horse and dressed as a knight, presents flowers to women during an event marking Valentine's Day in central Moscow, Russia, February 14, 2016. (Photo by Maxim Zmeyev/Reuters)

A diver dressed in a Santa Claus costume performs with sardines at the Coex Aquarium in Seoul, South Korea, Wednesday, December 9, 2015. (Photo by Ahn Young-joon/AP Photo)