Recycling artist Nicolas Gomez checks the strings of a cello he has made out of an oil barrel for the Orchestra of Recycled Instruments of Cateura, in Cateura, Paraguay February 13, 2015. Saudi Arabia's oil exports have risen in February in response to stronger demand from customers. As OPEC's top producer battles for market share Reuters photographers around the globe have been photographing oil barrels to document how they are utilised once the fuel has been used. (Photo by Jorge Adorno/Reuters)

In this February 19, 2014 photo, a skate seller puts slices of skate into styrofoam boxes for shipment to customers around South Korea at a fish market in Mokpo, a port city on the southwestern tip of the Korean Peninsula. The aroma of one of southwestern South Korea's most popular delicacies regularly gets compared to rotting garbage and filthy bathrooms. And that's by fans. The unusual dish is typically made by taking dozens of fresh skate, a cartilage-rich fish that looks like a stingray, stacking them up in a walk-in refrigerator and waiting. Up to a month in some cases. (Photo by Ahn Young-joon/AP Photo)

A model walks off stage in the backstage area during Frankie's Bikinis show at Mercedes Benz Swim Fashion Week in Miami, July 18, 2014. (Photo by Carlo Allegri/Reuters)

British soldiers inspect a captured German place in the Horseguards' Parade, London during World War I in November 1914, with the London Eye in the background as a reminder of just how much has changed in the last 100 years. (Photo by Peter Macdiarmid/Getty Images)

Tourists look at would-be immigrants at the Maspalomas beach, on Gran Canaria in Spain's Canary Islands, after some 21 would-be immigrants arrived in a fishing boat on their way to European soil from Africa, November 5, 2014. (Photo by Borja Suarez/Reuters)

A woman is tattooed by an artist during Warsaw Tattoo Convention 2014 in Warsaw November 29, 2014. (Photo by Kacper Pempel/Reuters)

A villager run as Mount Sinabung erupt at Sigarang-Garang village in Karo district, Indonesia's North Sumatra province, February 1, 2014. Four people died and more than 28, 000 villagers have been evacuated since authorities raised the alert status for the volcano to the highest level in November 2013, local media reported on Saturday. (Photo by Reuters/Stringer)

HRP-4C, a five-foot humanoid robot developed at Japan's National Institute of Advanced Industrial Science and Technology, sings and dances with performers at the Digital Contents Expo in Tokyo on October 17, 2010. The robot runs entertainment software called Choreonoid, a name formed from the words “choreograph” and “humanoid”. (Yoshikazu Tsuno/AFP)