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)

In this January 31, 2014 file photo released by the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA), shows residents of the besieged Palestinian camp of Yarmouk, queuing to receive food supplies, in Damascus, Syria. That year, the U.N. was able to deliver food to about five percent of people in besieged areas including Yarmouk, while today estimates show the organization is reaching less than one percent. (Photo by UNRWA via AP Photo)

A Free Syrian Army fighter walks past a flag of al-Furqan brigade as a rifle hangs from a branch in the orchards of Kafar Zita in Hama countryside January 22, 2015. (Photo by Mohamad Bayoush/Reuters)

A clothing shop displays its merchandise in the rebel-controlled city of Idlib, Syria November 7, 2015. (Photo by Ammar Abdullah/Reuters)

REUTLINGEN, GERMANY - NOVEMBER 17: Students hang out finished parchment leather at the LGR (Lederinstitut Gerberschule Reutlingen) tannery school on November 17, 2010 in Reutlingen, Germany. Even in early antiquity and up their hair or dried goat and sheep skins were used as material for documents. In the small Asian city Pergamon these skins were processed in large quantities for this purpose, so they formed the main trading arm of the city, of which the name is parchment is derived. In medieval times, reached the parchment is of great importance, it was such as France's production under the supervision of the University of Paris. Even now, important documents, placed on their unlimited shelf life as possible large value (eg diplomas, addresses, memory, writings, documents for primary and keystones) written on parchment...

A white lipizzaner Stallion performs during the Spanish Riding School of Vienna Gala Performance at Wembley Arena on November 24, 2011 in London, England. (Photo by Chris Jackson/Getty Images)

Students play in their school yard on the first day of the new school term at a primary school in Baghdad, October 18, 2015. (Photo by Ahmed Saad/Reuters)

Students of the "Escola de Papai Noel do Brasil" (Brazil's school of Santa Claus) travel on a ferry through Guanabara bay, during their graduation ceremony in Rio de Janeiro, Brazil, November 10, 2015. The school holds 4 days' lessons in Santa-training, teaching Christmas carols, how to interact with children, and also how to wear the heavy red suit in Rio's typical 104-degree (40 degrees celsius) summer weather that is common around the holidays. (Photo by Pilar Olivares/Reuters)