Tong Jieping, 44-year-old mentally disabled patient, is chained by his foot inside his room, in Qunxing village of Wangjiang county, Anhui province, China, July 14, 2015. Tong was diagnosed mentally ill when he was in his 20s. His parents, both in their 70s, could not afford the medical treatments so they had to lock him up in chains to prevent him from running away, according to Tong's family. (Photo by Reuters/Stringer)

Baloo (R), a North American Black Bear, rubs snouts with his companion Shere Hkhan, a Bengal tiger, inside their shared enclosure at Noah's Ark animal sanctuary in Locust Grove, Georgia, USA, 28 August 2014. According to the facility, the pair and a lion named Leo, were confiscated at a young age from a drug dealer's basement in Atlanta, Georgia. Noah's Ark cares for about 100 different species of animals on a 250 acre farm since 1990. (Photo by Erik S. Lesser/EPA)

A nurse consoles herself with a box of chocolates as she reads a paper-back thriller. (Photo by Hulton Archive/Getty Images). Circa 1955

Waves hit the seawall during heavy seas and high winds in Dawlish in south west Britain, February 2, 2017. (Photo by Toby Melville/Reuters)

A boy jumps into a pool of mud during the traditional “Bloco da Lama” or “Mud Street” carnival party, in Paraty, Brazil, Saturday, February 25, 2017. Legend has it the “bloco” was born in 1986 after local teens hiking in a nearby mangrove forest smeared themselves with mud to discourage mosquitoes and then wandered through Paraty. The party grew year after year, but revelers eventually were banned from parading in the colonial downtown after shopkeepers complained pristine white walls were stained with the hard-to-remove mud. (Photo by Mauro Pimentel/AP Photo)

Participants, one of them loosing balance, jump in a sack race at a shopping center in Paris to win a 500 euros voucher (537 USD), on the first day of the winter sales in Paris, France, Wednesday, January 6 , 2016. The five-week 2016 winter sales start everywhere across France on Wednesday Jan. 6 and end on Feb. 16. (Photo by Francois Mori/AP Photo)

A pilot inflates a hot air balloon while taking part in the 38th International Balloon Festival of Chateau-d'oex, Switzerland, 23 January 2016. The festival takes place from 23 to 31 January. (Photo by Vincent Vannay/EPA)

A U.S. Army soldier with the 10th Special Forces Group and his military working dog jump off the ramp of a CH-47 Chinook helicopter from the 160th Special Operations Aviation Regiment during water training over the Gulf of Mexico as part of exercise Emerald Warrior 2011 on March 1, 2011. (Photo by Tech. Sgt. Manuel J. Martinez/U.S. Air Force)