Yang Shiguang, 77, performs stunts at a park in Xi'an, Shaanxi province, September 3, 2013. Yang has been a member of a stunt performance club since 2007, after retiring from a research institution. (Photo by Reuters/China Daily)

Sisters await the arrival of the caravan carrying the late Cuban President Fidel Castro's ashes in El Maja, Cuba, December 1, 2016. (Photo by Edgard Garrido/Reuters)

A man presents a self-made robot that local media reported is able to carry a person, in Heihe, Heilongjiang province, China, April 5, 2017. (Photo by Reuters/China Daily)

Soldiers pose for a photo during the flower exhibition marking the 105th birth anniversary of the country's founding father, Kim Il Sung in Pyongyang, North Korea April 16, 2017. (Photo by Damir Sagolj/Reuters)

Children play on a donkey cart belonging to an elderly Afghan refugee sleeping on a roadside on the outskirts of Islamabad, Pakistan, Wednesday, February 18, 2015. (Photo by Muhammed Muheisen/AP Photo)

Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)

A jockey falls from his buffalos during Barapan Kebo or buffalo races as part of the Moyo festival on September 30, 2014 in Sumbawa Island, West Nusa Tenggara, Indonesia. The traditional Buffalo races, known as Barapan Kebo, are held by Samawa tribes in muddy rice fields to celebrate and provide entertainment ahead of the annual planting season. Jockeys secure themselves on a wooden structure attached to the buffalo, and maneuver across the mud in a race to the finish line. The jockeys weild long sticks, in a similar style to jousting, and direct them towards targets called “Saka”. (Photo by Ulet Ifansasti/Getty Images)

Young men play basketball on an improvised court wedged between a construction site and the shells of once grand colonial homes in Havana, July 20, 2015. As much as the young in Cuba welcome political opening and economic reform, such changes are unlikely to filter down to their lives anytime soon. (Photo by Meridith Kohut/The New York Times)