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)

Children, wearing red neckerchiefs, a symbol of the Pioneer Organization, salute during a ceremony for the inauguration of 18 new members at a local school in the southern settlement of Kazminskoye in Stavropol region, Russia, November 19, 2015. Early pro-communist youth movements, which appeared in Russia after the 1917 Bolshevik revolution, were reformed into the Pioneer Organization of the Soviet Union. While the organization lost its dominance among students in post-Soviet Russia, some educational institutions and families still carry on this tradition. (Photo by Eduard Korniyenko/Reuters)

An internally displaced girl stands on an abandoned railway tracks beside a makeshift refugee camp in Sinjar town, in Idlib province, Syria November 20, 2015. (Photo by Ammar Abdullah/Reuters)

Members of the New People's Army (NPA) female guerrillas perform a cultural show during the release of a Philippines army soldier in Sugbongcogon town, Misamis Oriental, southern Philippines, November 20, 2015. NPA spokesperson Allan Juanito warned that they will seize more soldiers to exchange them with the government as "Prisoners of war". (Photo by Froilan Gallardo/Reuters)

This picture taken on November 18, 2015 shows young participants preparing to release a hot-air balloon during the Tazaungdaing Lighting Festival at Taunggyi in Myanmar's northeastern Shan State. Every year in November as the full moon approaches, tens of thousands of people from all over the country gather in Taunggyi for the colourful hot-air balloons festival during which balloons lift fireworks or lanterns which illuminate the sky at night while balloons of all shapes are flown during the day. (Photo by Ye Aung Thu/AFP Photo)

Devil Ark manager Dean Reid reacts as Tasmanian Devil joeys climb on him before the first shipment of healthy and genetically diverse devils to the island state of Tasmania leave the Devil Ark sanctuary in Barrington Tops on Australia's mainland, November 17, 2015. The largest group so far of disease-free Tasmanian devils has been released in the wild, as part of plans to save the carnivorous marsupials from a cancer threatening them with extinction. (Photo by Jason Reed/Reuters)

In this November 18, 2015 photo, 9-year-old Mahiro Takano, center, three-time Japan karate champion in her age group practices in Nagaoka, Niigata Prefecture, north of Tokyo. Mahiro stars in singer Sia's latest music video "Alive", the just-released single from the singer's upcoming album. (Photo by Eugene Hoshiko/AP Photo)

Ricky Martin perfoms "La Mordidita" during the Latin Recording Academy Person of the Year gala honoring Brazilian singer Roberto Carlos in Las Vegas, Nevada November 18, 2015. (Photo by Mario Anzuoni/Reuters)