A boy carries empty sacks after bringing different types of plastic materials to a recycling station in Khartoum North April 16, 2015. People bring bottles and other plastic materials to the station for recycling, and get paid in return. (Photo by Mohamed Nureldin Abdallah/Reuters)

Some women doing yoga pose on the hammocks during the Anti-Gravity yoga class at Svarga e-Motion Sanctuary at Dharmawangsa Square, Jakarta, Saturday, April 18, 2015. Anti-Gravity Yoga or “aerial yoga”, is a new type of yoga, originating in New York but now being practised in several countries, which combines the traditional yoga poses, pilates and dance with the use of a hammock. (Photo by Jurnasyanto Sukarno/JG Photo)

A girl looks out from the window of a “La Sabana” tourist train in La Caro March 1, 2015. The “La Sabana” tourist train that runs through the capital was founded by Eduardo Rodriguez, a railway engineer. Rodriguez has worked on Colombia's railway system his whole life and now, with an air of nostalgia, transports thousands of tourists in renovated steam locomotives that he fixes in Bogota's Central Station which dates back to 1913. (Photo by Jose Miguel Gomez/Reuters)

An Israeli boy looks through the sight of a weapon during a display of Israeli Defense Forces (IDF) equipment and abilities at the West Bank settlement of Kiryat Arba, April 23, 2015, during celebrations for Israel's Independence Day, marking the 67th anniversary of the creation of the state. (Photo by Ronen Zvulun/Reuters)

Angora rabbit Emilson sits next to its freshly shaved hair at Georgia Spausta's small farm in Herzogbirbaum, Austria March 10, 2015. Spausta produces hand-spun yarn from some 25 angora rabbits which is sold in small scale to enthusiasts or at local markets. The rabbits are clipped four times a year, each time giving some 300 grams of wool, about the amount needed to knit one pullover. (Photo by Heinz-Peter Bader/Reuters)

French climber Alain Robert, also known as “Spiderman”, holds the flag of Nepal as he scales the Tour Montparnasse, a 210-metre (689 ft) building in central Paris, France April 28, 2015, to show support for the victims after the earthquake in Nepal. (Photo by Gonzalo Fuentes/Reuters)

Russian servicemen drive a partially covered T-14 Armata tank along a street before a rehearsal for the Victory Day parade in Moscow, Russia, April 29, 2015. Russia will celebrate the 70th anniversary of the victory over Nazi Germany in World War Two on May 9. (Photo by Maxim Zmeyev/Reuters)

Vietnamese military personnel in traditional dress take part in a parade celebrating the 40th anniversary of the end of the Vietnam War which is also remembered as the fall of Saigon, in Ho Chi Minh City, Vietnam, Thursday, April 30, 2015. (Photo by Dita Alangkara/AP Photo)