Food is placed on the tomb of pet dog Xixi at Baifu pet cemetery ahead of the Qingming Festival on the outskirts of Beijing, China March 26, 2016. The Chinese characters on the gravestone read: “Mommy's only good son”. (Photo by Jason Lee/Reuters)

A young monk takes his food from the dining hall at Changangkha Lhakhang temple in Thimphu, Bhutan, April 13, 2016. (Photo by Cathal McNaughton/Reuters)

A young Afghan vendor waits for customers to buy sheep's heads at a roadside stall at the busy market in Kabul on November 29, 2015. (Photo by Wakil Kohsar/AFP Photo)

This picture taken on November 9, 2014 shows sharks for sale as a man removes the fins at a traditional market in Tanjung Luar in Lombok, West Nusa Teggara. Hundreds of sharks are hauled ashore every day at a busy market on the central Indonesian island of Lombok, the hub of a booming trade that provides a livelihood for local fishermen but is increasingly alarming environmentalists. The fins are sold to other Asian nations, including Singapore, Hong Kong and Taiwan, where shark-fin soup is considered a delicacy. (Photo by Sonny Tumbelaka/AFP Photo)

A worker paints the Amazon Tall Tower Observatory (ATTO) in Sao Sebastiao do Uatuma in the middle of the Amazon forest in Amazonas state January 10, 2015. The Amazon Tall Tower Observatory is a project of Brazil's National Institute of Amazonian Research and Germany's Max Planck Institute and will be equipped with high-tech instruments and an observatory to monitor relationships between the jungle and the atmosphere from next July. According to the institutes, ATTO will gather data on heat, water, carbon gas, winds, cloud formation and weather patterns. (Photo by Bruno Kelly/Reuters)

A woman, covered in mud, dances during the traditional “Bloco da Lama” or “Mud Block” carnival party, in Paraty, Brazil, Saturday, February 14, 2015. Revelers in the seaside colonial town threw themselves into deposits of black, mineral-rich slime, emerging covered head-to-toe in the sludge. Bikinis and trunks disappeared beneath the mud, which highlights both gym-pumped pectorals and beer-fed guts. (Photo by Leo Correa/AP Photo)

Two women jump into a frozen pond as they compete in the Polar Plunge at Frozen Dead Guy Days in Nederland, Colorado March 14, 2015. The winter festival in the small mountain town commemorates the 1994 discovery of the corpse of Bredo Morstol, which is now housed in a shed on dry ice above the town. (Photo by Rick Wilking/Reuters)

Eurocopter's X³ high-speed hybrid helicopter demonstrator performs, September 6, 2010. The Eurocopter X³ (X-Cubed) is an experimental high-speed compound helicopter developed by Eurocopter (now Airbus Helicopters). A technology demonstration platform for Eurocopter “high-speed, long-range hybrid helicopter” or H³ concept, the X³ achieved 255 knots in level flight on 7 June 2013, setting an unofficial speed record for a helicopter. (Photo by Reuters/HO/Eurocopter/Penna)