A passenger waits after his train arrived in Nouadhibou, Mauritania’s second largest city and the main export port for the country’s iron ore industry, on June 25, 2014. The mining company’s employees proudly call their firm the lung of their nation's economy and the train that ferries the ore to the coast stretches some two kilometres, making it one of the world's longest. SNIM mines black iron ore in the northern town of Zouerate, a remote desert location which nevertheless attracts people from all over the country looking for work. (Photo by Joe Penney/Reuters)

A woman waters the plants outside her house in an alley at a slum in Mumbai October 28, 2014. (Photo by Danish Siddiqui/Reuters)

An alpaca chewing a leaf is pictured on November 18, 2014 in the zoo of Frankfurt am Main, Germany. (Photo by Frank Rumpenhorst/AFP Photo/DPA)

A boy jumps from a swing during sunset in Valras-Plage, southern France December 29, 2014. (Photo by Yves Herman/Reuters)

In this January 23, 2015 photo, Guillermo Luna Martinez, 36, carries freshly painted piñatas representing Disney's Frozen snowman character Olaf downstairs to where his wife Elvia Vicente Albarran will use paper to craft the character's eyes, teeth, and distinctive tuft of hair, at the family's workshop in the Iztapalapa neighborhood of Mexico City. Though Luna and his wife have chosen to work in the family business, they plan to let their children, Guillermo, 10, and Melissa, 9, decide for themselves. “Who knows if the business will last forever”, said Luna, “I'd prefer that they study and get a career, for them to have a better future”. (Photo by Rebecca Blackwell/AP Photo)

A 19th century bicycle safety lock is displayed in an old frame in the Museum of Domenico Agostinelli in Dragona, near Rome October 30, 2014Italian collector Domenico Agostinelli, 74, has a passion that has led him over the past 60 years to pick up and collect things of all types, from antique art to everyday objects of the past and present. His collection includes a 65-million-year-old dinosaur egg, meteor fragments, a car that once belonged to American mob boss Al Capone, a lock of hair of Italian national hero Giuseppe Garibaldi, toys, weapons, musical instruments of all kinds and many more. (Photo by Tony Gentile/Reuters)

In this Wednesday, March 18, 2015 photo, limestone quarry workers walk through a cloud of dust spewed into the air by rotor blades of the stone-cutting machinery in the desert of Minya, southern Egypt. Around 45,000 people, including children, work in an estimated 1,500 quarries, digging out stones that later will be used in construction or powdered to be used by pharmaceutical and ceramic companies. (Photo by Mosa'ab Elshamy/AP Photo)

Spanish runner Francisco Contreras, 77, known as “Super Paco”, runs as he participates in the XVIII 101km international competition in the outskirts of Ronda, southern Spain, May 9, 2015. About 7,000 participants, including runners, mountain bikers and duathletes, run a track of 101 km (63 miles) in less than 24 hours through the “Serrania de Ronda” (Ronda Mountain Range) during this competition organised by the 4th Tercio (Regiment) “Alejandro Farnesio” of the Spanish Legion. The Puente Nuevo is 120 metres (394 feet) high over the gorge of the river that divides the city of Ronda. Picture taken using long exposure. (Photo by Jon Nazca/Reuters)