A competitor scrambles in the mud under barbed wire during the Tough Guy Challenge 2009 at South Perton Farm on February 1, 2009 in Wolverhampton, England. The biannual event to raise cash for charity challenges thousands of international competitors to run through a gruelling set of 21 obstacles including water, fire and tunnels after a lengthy run at the start. (Photo by Christopher Furlong/Getty Images)

An Emperor Tamarin monkey, native to the Amazon rainforest, experiences its new home in the living rainforest enclosure at ZSL London Zoo on March 25, 2010 in London, England. Entitled “Rainforest Life” the large temperature and humidity controlled bio-dome is home to free-roaming monkeys, sloths, tree anteaters and tropical birds. The exhibit, which is opening in the International Year of Biodiversity, will be open to the public from March 27, 2010. (Photo by Oli Scarff/Getty Images)

A Participant attends the opening of the first Jordanian International Horseback Archery competition, also known as the Al Faris competition and organized by the Public Security, to mark the country's 65th Independence Day June 9, 2011 in Amman, Jordan. The Al Faris competition involves showcasing different archery styles and competitors from more than fifteen countries. (Photo by Salah Malkawi/ Getty Images)

Nigerian fashion models are made up for their fashion show to promote ethnic fashion June 13, 2006 in Tel Aviv, Israel. The models said they hope to use the travelling show as a springboard to international fame, in the words of one, “to be the next Naomi Campbell”. (Photo by Uriel Sinai/Getty Images)

Farmers harvest cocoa fruits at a plantation in Gantarang Keke Village, South Sulawesi, Indonesia May 8, 2015. Sulawesi is at the heart of Asia's largest cocoa producing region, and is where some international confectioners are looking to boost output to feed growing demand for chocolate in the region. (Photo by Yusuf Ahmad/Reuters)

Damaged vehicles sit on Yeongjong Bridge in Incheon, South Korea, Wednesday, February 11, 2015. Two people were killed and at least 42 were injured on Wednesday after a pileup involving about 100 vehicles in foggy weather on the bridge near the Incheon International Airport, South Korean officials said. (Photo by Suh Myung-gon/AP Photo/Yonhap)

A solar-powered plane takes off from Jiangbei International Airport in southwest China's Chongqing Municipality, Tuesday, April 21, 2015. The Solar Impulse 2 departed Chongqing on Tuesday for a 1190-kilometer (642-mile) flight to the city of Nanjing in eastern China, the sixth leg of its around-the-world flight. (Photo by Chinatopix via AP Photo)

“A robot suit that can help the elderly or disabled get around was given its global safety certificate in Japan on February 27, 2013, paving the way for its worldwide roll-out”. Photo: Robot suit “Hybrid Assistive Limb (HAL)” worn by a man developed by University of Tsukuba is seen lifting a 30kg weight during 2005 International Robot Exhibition on November 30, 2005 in Tokyo, Japan. By wearing the power suit, it makes it easier to move and lift heavy things. (Photo by Koichi Kamoshida)