A student from “the cliff village” in Atule'er climbs newly-constructed steel ladders after school to go home for holidays, in Liangshan Sichuan province, China, November 19, 2016. The steel ladders which replaced the unsafe vine ladders shortened the time taken for the children to go home, from three hours to two. (Photo by Reuters/Stringer)

A supporter of the Houthi movement attends a rally marking the birth anniversary of Prophet Mohammed, in Sanaa, Yemen December 11, 2016. (Photo by Khaled Abdullah/Reuters)

Tyson the Bulldog sits with reindeer antlers on Christmas Day at Central Park in Manhattan, New York City, U.S., December 25, 2016. (Photo by Andrew Kelly/Reuters)

Carolina Gutierrez (center L), 17, and Neuil Valdez, 18, use mobile phones to connect to the internet at a hotspot in downtown Havana, Cuba, December 12, 2016. (Photo by Alexandre Meneghini/Reuters)

Afghan girl athletes perform Wushu on the top of a hill in Kabul, capital of Afghanistan, January 18, 2017. In the conservative Afghan society where people especially in the countryside deeply believe in the old traditions and don't allow their girls and female members of the family to go out of home, exercising sport in open is extremely risky, but a group of girls are broken the taboo and exercising Wushu on a hilltop where the temperature is minus 2 Celsius degrees. (Photo by Rahmat Alizadah/Xinhua/Barcroft Images)

A girl wearing a butterfly headband poses for a picture near damaged buildings in the rebel held besieged city of Douma, in the eastern Damascus suburb of Ghouta, Syria January 19, 2017. (Photo by Bassam Khabieh/Reuters)

Street vendors carry chickens for sale at Kawran Bazar in Dhaka, Bangladesh January 25, 2017. (Photo by Mohammad Ponir Hossain/Reuters)

Passengers wait at the departure hall of the Beijing Railway Station in central Beijing, China January 27, 2017 as China gears up for Lunar New Year, when hundreds of millions of people head home. (Photo by Damir Sagolj/Reuters)