Palestinian schoolboys sit in the trunk of a car as they go to school on a rainy day in Khan Younis, in the southern Gaza Strip, October 7, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

Pope Francis waves as he arrives at the Kangemi slums on the outskirts of Kenya's capital Nairobi, November 27, 2015. (Photo by Goran Tomasevic/Reuters)

Pakistani street performers sit around fire waiting for customers on a chilly evening in Rawalpindi, Pakistan, Wednesday, November 11, 2015. Some parts of Pakistan are facing a harsh winter. (Photo by B. K. Bangash/AP Photo)

Ecuadorean spontaneous bullfighters participate in a popular bull festival called Las Canteras del Antisana at Pinantura village on the base of the Antisana volcano in Quito, November 28, 2015. (Photo by Guillermo Granja/Reuters)

A light installation is seen on the facade on the banks of the Saone river to pay tribute to the victims of the Paris attacks in Lyon, France, December 8, 2015. (Photo by Robert Pratta/Reuters)

Policewomen take a picture inside a tunnel under the Chao Phraya river at a Mass Rapid Transit subway station in Bangkok, Thailand, December 14, 2015. (Photo by Athit Perawongmetha/Reuters)

Members of the ice swimming club “Berliner Seehunde” (Berlin Seals) take a dip in the Orankesee lake as part of their traditional Christmas swimming session in Berlin, Germany, December 25, 2015. (Photo by Hannibal Hanschke/Reuters)

Internally displaced Syrian children stand at the entrance of their makeshift shelter that is an underground cave in Om al-Seer, southern Idlib countryside, Syria December 26, 2015. (Photo by Khalil Ashawi/Reuters)