A herdsman stands on the back of a grey bull during a ceremony of driving sheep from their winter habitat to their summer pasture in the puszta or Hungarian steppe of Hortobagy, 183 kms east of Budapest, Hungary, 23 April 2016. Sheep are traditionally driven to their summer pasture at around St. George's Day in the Hortobagy region, because livestock breeding people traditionally consider St. George's Day the beginning of spring. (Photo by Zsolt Czegledi/EPA)

David Reutimann, driver of the #00 Aaron's Dream Machine Toyota, Brian Vickers, driver of the #83 Red Bull Toyota, and Denny Hamlin, driver of the #11 FedEx Express Toyota, collide after an incident in the NASCAR Sprint Cup Series Jeff Byrd 500 Presented By Food City at Bristol Motor Speedway on March 20, 2011 in Bristol, Tennessee.

Florida Division of Forestry fire fighter, Tim Abramczyk, sprays foam on a hotspot that flared up as he works on containing a 50,316-acre brush fire on June 10, 2011 in West Dade, Florida. The fire started last weekend as South Florida continues to endure a dry start to the rainy season and drought conditions have begun to appear. The forestry division has the fire about 55 percent contained. (Photo by Joe Raedle/Getty Images)

“The 8th annual Water War on Friday in the center of Tel-Aviv, Israel turned into a battlefield, quite literally. As two thousand people were having fun in the square, some water-fighters took to more radical behavior, targeting passing cars, motorcycles and public buses”. – iReport.cnn.com (Photo by Sergey Demyanchuk)

A fighter jet flies above as Ukrainian soldiers sit on an armoured personnel carrier in Kramatorsk, in eastern Ukraine April 16, 2014. Ukrainian government forces and separatist pro-Russian militia staged rival shows of force in eastern Ukraine on Wednesday amid escalating rhetoric on the eve of crucial four-power talks in Geneva on the former Soviet country's future. (Photo by Marko Djurica/Reuters)

In this January 4, 2016 photo, the weapon of a rebel fighter for the 36th Front of the Revolutionary Armed Forces of Colombia, or FARC, hangs from a branch serving as a makeshift clothesline, near a rebel camp, in Antioquia state, in the northwest Andes of Colombia. “We’ll lay aside our weapons, like the accord says, but never hand them over”, says Juan Pablo, a commander of the 36th Front. (Photo by Rodrigo Abd/AP Photo)