Pupils of the Dao ethnic tribe return home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)

Afghan women and a boy make their way in Kabul, Afghanistan, Sunday, November 15, 2015. (Photo by Rahmat Gul/AP Photo)

Contestants for the Miss World grand final perform in colourful costumes during a dress rehearsal in Sanya, Hainan province, China, 18 December 2015. (Photo by How Hwee Young/EPA)

Claudionor Jose de Deus, wearing a Santa Claus costume, arrives at Santa Rosa community to distribute presents to children, on the shores of the Amazon River in rural Manaus, Brazil, December 19, 2015. Jose de Deus is part of a volunteer group that distributes toys to children from poor neighborhoods and riverside communities that are distant from the city. (Photo by Bruno Kelly/Reuters)

In this Tuesday, December 15, 2015 photo, an Afghan man sells traditional sauces and pickles on a street in Kabul, Afghanistan. (Photo by Massoud Hossaini/AP Photo)

Children play football in front of an abandoned train compartment next to a railway track in Dhaka, in this May 29, 2014 file photo. (Photo by Andrew Biraj/Reuters)

Jiejin Qiu, who is six months pregnant with her first baby, poses underwater during a photo shoot at a local wedding photo studio in Shanghai, in this September 5, 2014 file photo. (Photo by Carlos Barria/Reuters)

A woman reacts as anti-government protesters place a dead body on a stretcher after violence erupted in the Independence Square in Kiev, in this February 20, 2014 file photo. (Photo by Vasily Fedosenko/Reuters)