A boy rides on a snow wagon towed by a robot dressed as a Teddy bear, which only moves forward by moving its legs, during the Ice and snow carnival at Taoranting park in Beijing February 9, 2015. (Photo by Kim Kyung-Hoon/Reuters)

This Monday, September 15, 2014 photo shows glazed bricks displayed at the Iraqi National Museum in Baghdad. The Islamic State militants seek to purge society of all influences that don't conform with their strict, puritanical version of Islam. That means destroying not only relics seen as pagan but also Muslim sites they see as contradicting their ideology, particularly Sunni Muslim shrines they see as idolatrous as well as mosques used by Shiites, a branch of Islam they consider heretical. (Photo by Hadi Mizban/AP Photo)

A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

Romanian military doctors and medical students sit on a bus behind steamy windows before the National Day parade in Bucharest, Romania, Thursday, December 1, 2016. Military planes and helicopters flew over the Romanian capital Thursday as thousands turned out to celebrate the national day, marking the date when the country reunified with Transylvania in 1918. (Photo by Vadim Ghirda/AP Photo)

A man dressed as Father Frost, Russian equivalent of Santa Claus, sits by the fire with a reindeer Yakut, marking winter solstice at the Royev Ruchey Park of Flora and Fauna in the Siberian Taiga wood in the suburbs of Krasnoyarsk, Russia, December 21, 2016. (Photo by Ilya Naymushin/Reuters)

Participants wear traditional clogs as shepherds lead their sheep through the center of Madrid, October 28, 2012. (Photo by Andres Kudacki/Associated Press)

Bride Yulia Tagil sits on the backseat of a bike as she arrives for her alternative wedding ceremony on a square in Tel Aviv July 25, 2010. The alternative wedding ceremony was intended to demonstrate against the current situation in Israel, where the only way for Jews to get married by law is through the Chief Rabbinate. (Photo by Nir Elias/Reuters)