A worker spreads paddy crop for drying in a rice mill complex on the outskirts of Ahmedabad February 3, 2011. (Photo by Amit Dave/Reuters)

A model falls while displaying a design from Wu Xuewei and Wu Xuekai, winners of the Asahi Kasei China Fashion Designer Award during China Fashion Week held in Beijing, China, Friday, October 29, 2010. (Photo by Ng Han Guan/AP Photo)

Yu Jietao, 26-year-old wood carver, sits in his homemade wooden car along a street in Guangfeng county of Shangrao, Jiangxi province, China February 9, 2015. The car can travel as fast as 30 km (18.6 miles) per hour, local media reported. (Photo by Reuters/Stringer)

Kumbuka, a male silverback gorilla sits next to the keeper's chalk board in his enclosure at London Zoo, Thursday, January 2, 2014. Home to more than 850 different species, zoo keepers welcomed in the New Year armed with clipboards as they made a note of every single animal. The compulsory annual count is required as part of ZSL London Zoo's zoo license, and every creature, from the tiny leaf cutter ants to the huge silverback gorilla is duly noted and accounted for. (Photo by Kirsty Wigglesworth/AP Photo)

An Israeli army officer gives explanations to journalists during an army organised tour in a tunnel said to be used by Palestinian militants for cross-border attacks, July 25, 2014. (Photo by Jack Guez/Reuters)

A girl carries fire wood collected from flood waters in the flood affected Morigaon district of Assam state, India, 25 July 2016. Over half a million people of 15 districts in Assam state have been affected by the current wave of floods. According to the media reports more than 70 relief camps have been set up in the affected districts to provide shelter to the flood affected people. (Photo by EPA/Stringer)

David Sharp, an engineer with Lockheed Martin, displays the “Samurai Flyer”, an aviation design inspired by the maple seed, during the Association for Unmanned Vehicle Systems International Conference August 16, 2011 in Washington, DC. Lockheed Martin unveiled the new design and demonstrated vertical takeoff and landing, stable hover, and on-board video streaming of the aircraft during their demonstration. (Photo by Win McNamee/Getty Images)