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)

A man reacts over dead bodies prior to burial in a graveyard after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria, October 24, 2016. (Photo by Bassam Khabieh/Reuters)

“Kids of Sapa”. Four little beautiful Hmong girls from Lao Chai Village, near Sapa, Vietnam. (Photo and caption by Felipe Hanower/National Geographic Traveler Photo Contest)

Sarah Bui poses for photographer, Brian Le around blossoming cherry trees, near the Tidal Basin on Thursday March 23, 2017 in Washington, DC. (Photo by Matt McClain/The Washington Post)

Iraqi paramilitary troops fire towards Islamic State militants during a battle with Islamic State militants on the outskirts of the ancient city of Hatra near Mosul,Iraq April 26, 2017. (Photo by Reuters/Stringer)

Potters colour earthen lamps at a workshop ahead of the Hindu festival of Diwali in Amritsar October 15, 2014. Earthen lamps are sold in large numbers during Diwali, the annual Hindu festival of lights, as people use them to decorate their homes. (Photo by Munish Sharma/Reuters)

Onlookers gather around a struggling beached whale in the Yoff neighborhood of Dakar, Senegal Wednesday, May 21, 2008. Residents worked Wednesday morning to save some of the more than 80 whales that were stranded on the beach Tuesday night. This whale was successfully towed out to sea by a fishing boat, though at least 20 others lay dead on the beach by midday Wednesday. (Photo by Rebecca Blackwell/AP Photo)

South American sea lion. Valencia, February 8, 2012. (Photo by Ger Art; Source: Flickr)