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)

A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

Tourists walk behind a faded sign warning of tsunami hazard in Khao Lak, Phang Nga province December 15, 2014. Ahead of the anniversary of the 2004 tsunami, experts and officials say key weaknesses remain across the region in the system designed to warn people of the next disaster, and get them to safety. Thailand prepares to mark the tenth anniversary of the 2004 tsunami, the deadliest on the record, that killed at least 226,000 people in 13 Asian and African countries. (Photo by Damir Sagolj/Reuters)

In this June 1, 2016 photo, Maria Arias stands near her kitchen as she puts on earrings while getting ready for school in Caracas, Venezuela. So many students have fainted from hunger at Maria's school that administrators told parents to keep their children home until they could find more food. (Photo by Ariana Cubillos/AP Photo)

A photo taken on August 29, 2014, shows Mount Tavurvur erupting in eastern Papua New Guinea, spewing rocks and ash into the air, forcing the evacuation of local communities and international flights to be re-routed. Mount Tavurvur, which destroyed the town of Rabaul when it erupted simultaneously with nearby Mount Vulcan in 1994, rumbled to life early in the morning on the tip of the remote island of New Britain. (Photo by Oliver Bluett/AFP Photo)

A team of ten acrobats form the shape of a racehorse crossing the winning post ridden by Stefanie Hofer to celebrate the upcoming Dubai Duty Free Shergar Cup at Ascot Racecourse on July 29, 2014 in Ascot, England. The Dubai Duty Free Shergar Cup is the only team-format raceday in the UK and takes place on 9th August. (Photo by Ian Gavan/Getty Images for Ascot Racecourse)

A model poses at Checkpoint Charlie, a historic place in the German capital to promote the fashion magazine “Sous” on June 12, 2012. (Photo by Maurizio Gambarini)

A weeping South Vietnamese mother and her three children are shown on the deck of this amphibious command ship being plucked out of Saigon by U.S. Marine helicopters in Vietnam, April 29, 1975. (Photo by AP Photo)