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)

A man makes traditional candy “Matang” in preparation for the upcoming Chinese Lunar New Year in Yuqing County, Zunyi, Guizhou Province, China, January 18, 2016. (Photo by Reuters/China Daily)

A Syrian boy looks through a gate as others wait to cross into Syria at Oncupinar border crossing in the southeastern city of Kilis, Turkey February 11, 2016.. (Photo by Osman Orsal/Reuters)

UFC women's bantamweight champion Holly Holm and Miesha Tate face off during the UFC 196 weigh ins at the MGM Grand Garden Arena in Las Vegas on Friday, March 4, 2016. (Photo by L.E. Baskow/Las Vegas Sun via AP Photo)

Marieke van der Meer from the Netherlands works on her sculpture “Flora” at the sand sculpture show in Binz on Ruegen island, Germany, 09 March 2016. With the motto “Fascination Nature”, 50 sand artists have created oversized sculptures. The sculptors use 16,000 tons of special sand that is pressed into big blocks first and then formed. The 7th sand sculpture show on 5,600 square meters of exhibition ground opens on 12 March 2016. (Photo by Ens Buettner/EPA)

A couple stands next to a poster depicting Dutch politician Geert Wilders and Russian President Vladimir Putin kissing, at a metro station in Amsterdam April 3, 2016. (Photo by Cris Toala Olivares/Reuters)

A competitor walks on tightrope during a performance in Taizhou, Zhejiang Province, China, May 7, 2016. (Photo by Reuters/China Daily)