A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)

Breitling Wingwalkers aircrafts perform during an aerobatic display at an air show in Zhengzhou, Henan province, China, September 25, 201. (Photo by Reuters/Stringer)

Russian soldiers from 34th motorized infantry mountain brigade, 58th Army, prepare to evacuate a fellow soldier acting as an injured person during a drill at the Darial range outside Russia's city of Vladikavkaz, July 28, 2010. (Photo by Kazbek Basayev/Reuters)

A female sniper of the Syrian Democratic Forces (SDF) monitors the area during a celebration at the iconic Al- Naim square in Raqa on October 19, 2017, after retaking the city from Islamic State (IS) group fighters. The SDF fighters flushed jihadist holdouts from Raqa' s main hospital and municipal stadium, wrapping up a more than four- month offensive against what used to be the inner sanctum of IS' s self- proclaimed “caliphate”. (Photo by Bulent Kilic/AFP Photo)

The Lake of Lights at Talkin Tarn lake near Brampton in Cumbria, England on October 22, 2017 – where hundreds of lights in the surrounding woodland represent a cherished memory of a relative friend or loved one no longer with us. (Photo by Owen Humphreys/PA Images via Getty Images)

11-year-old Balinese dancer girl Intan puts on makeup before she performs Mergapati Dance at a village event in Banjar Wangaye Kelod, Denpasar, Bali, Indonesia on November 19, 2017. To preserve traditional dances and culture, Balinese train their children to learn various traditional dances from childhood. (Photo by Mahendra Moonstar/Anadolu Agency/Getty Images)

In this Wednesday, November 15, 2017 photo, a woman poses for a selfie with the carcass of a humpback whale on Ipanema beach, in Rio de Janeiro, Brazil. Biologist Rafael Carvalho said the whale appears to have been dead for a few days. Authorities were urging beachgoers who had flocked to Ipanema on a national holiday to stay away from the animal. (Photo by Silvia Izquierdo/AP Photo)

People walk past stranded cargo ship “Ocean Crown” during a windy weather in Klaipeda, Lithuania on December 26, 2017. (Photo by Ints Kalnins/Reuters)