Two F-15E Strike Eagles wait to receive fuel from a KC-135R Stratotanker during exercise Red Flag 15-1 on their way to Nellis Air Force Base, Nev., Jauary 23, 2015. The F-15s are assigned to the 4th Fighter Wing. U.S. (Photo by Airman 1st Class Aaron J. Jenne/Reuters)

Ultra-Orthodox Jews knead dough in a bakery in an Orthodox neighborhood in Jerusalem, 29 March 2015. Matzah, or unleavened bread, is used instead of bread during the week-long Jewish holiday of Passover, commemorating the Jewish exodus from Egypt in Biblical times. (Photo by Abir Sultan/EPA)

A child wades through the mud next to a grave inside the flooded cemetery in Los Loros town, April 7, 2015. The death toll from heavy rains and flooding that battered Chile last week has risen to 29, with another 150 still missing, according to authorities. (Photo by Ivan Alvarado/Reuters)

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)

Wearing his new prosthetic legs Hero gets a taste of shrubbery Wednesday, May 21, 2014, in Houston. The abandoned calf rescued from a Virginia farm a year ago and brought to Texas after it nearly died is getting permanent prosthetics to replace back hooves that had to be amputated because of frostbite. (Photo by Pat Sullivan/AP Photo)

“Aurora Hunters”. Photographers taking part in a photography tour on the Lofoten Islands in Norway, pull over on the side of the road to take a photo of their first ever Aurora Borealis after spotting it from their tour bus. Photo location: Rystad, Lofoten Islands, Norway. (Photo and caption by Mark Gee/National Geographic Photo Contest)

Players battle for the ball during their match at the swamp soccer China tournament in Beijing, June 26, 2014. The 32 teams from across the country participated in the soccer event to celebrate the 2014 World Cup in Brazil. (Photo by Kim Kyung-Hoon/Reuters)

Buses are stranded in a flooded street in Fuzhou, Fujian province, July 24, 2014. Typhoon Matmo hit Taiwan on Wednesday, bringing heavy rain and strong winds, shutting financial markets and schools. It passed the island and headed into China, downgraded from typhoon to tropical storm. (Photo by Reuters/Stringer)