A prototype battery-powered plane, called Greased Lightning or GL-10 is pictured flying at NASA's Langley Research Center in this undated handout photo obtained by Reuters May 1, 2015. The plane, which has 10 engines and can take off like a helicopter and fly efficiently like an aircraft, is currently in the design and testing phase. (Photo by Reuters/NASA)

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)

Christian people crowd a bush taxi on a road 55km north of Bangui as they are on their way to the capital where they expect to sell some products on the market on January 19, 2014. Fresh fighting broke out in the strife-torn Central African Republic on the eve of an announcement on Sunday of the candidates seeking to become the new interim president. Sectarian violence has gripped the landlocked country after a March 2013 coup launched by the mostly Muslim Seleka rebels, and the UN has warned that the bloodshed could turn into genocide. (Photo by Eric Feferberg/AFP Photo)

Dog puppy “Sandy” protects against the rain with an umbrella fixed on her leash during a stroll in Rust, southern Germany, on May 26, 2013. (Photo by Patrick Seeger/AFP Photo)

History Created on 15th June 92 Young poor & Physically challenged Couples tied in a lifelong knot of Marriage “Free of Cost” Combined Marriage Function at Ramlila Ground on behalf of “Narayan Sewa Sansthan”. “Although we are unable to move without the support of a crutch or might take the help of others in performing every activity, still, we can afford to become a support for each other”. With this spirit, 92 young disabled and poor brides &bridegrooms promised to support each other throughout their life. The historical Ramliila Ground of Delhi became the witness of this mega event. Photo: Mass wedding in Delhi.

Workers demonstrate outside the factory of Hua Yang Printing Holdings Co Ltd on October 30, 2007 in Shenzhen of Guangdong Province, China. Over 1,000 workers of the company have blocked the 107 State Highway where the firm is located, to protest against their employer, who owed half a month's salary to the workers. (Photo by China Photos/Getty Images)

Young monks laugh at their own photos taken by a German photojournalist in the main courtyard of the Dzong on October 13, 2011 in Punakha, Bhutan. King Jigme Khesar Namgyel Wangchuck, 31 and Queen of Bhutan Ashi Jetsun Pema Wangchuck, 21 wed in Bhutan's historic 17th century Punakha Dzong the same venue that hosted the King's historical coronation ceremony in 2008. (Photo by Triston Yeo/Getty Images)

Debris fly into the air as foreign fishing boats are blown up by Indonesian Navy off Batam Island, Indonesia, Monday, February 22, 2016. Authorities on Monday sank dozens of fishing boats caught operating illegally in Indonesian waters as part of the country's campaign to battle illegal fishing. (Photo by M. Urip/AP Photo)