Two biplanes of the Team Breitling cross during a training flight prior the AIR14 air show in Payerne, Switzerland, August 29, 2014. (Photo by Peter Schneider/EPA)

Members of the U.S. Army 173rd Airborne Brigade stand at attention as a Ukrainian folk dance group performs at the opening ceremony of the “Rapid Trident” NATO military exercises on September 15, 2014 near Yavorov, Ukraine. The two-week exercises include participating units from a variety of NATO and NATO-associate countries as well as Ukrainian troops. Meanwhile fighting between pro-Russian separatists and Ukrainian armed foces has flared again in eastern Ukraine in a battle for the control of Donetsk airport despite the tenuous ceasefire. (Photo by Sean Gallup/Getty Images)

Friends of Li Guojun drive a homemade tank-shaped vehicle in Kangping county, China. Li, a farmer who is a fan of tanks, spent six months with help from his friends to construct the almost 20-foot vehicle which weighs 2.5 tons. (Photo by Sheng Li/Reuters)

“Warming up”. This photo I capture in the early afternoon, the animal species of lemurs fly. Photo location: Sambas, West Kalimantan, Indonesia. (Photo and caption by Hendy Mp/National Geographic Photo Contest)

A woman photographs “Super Space Titan Kitty” by Colin Christian at the “Hello! Exploring the Supercute World of Hello Kitty” museum exhibit in honor of Hello Kitty's 40th anniversary, at the Japanese American National Museum in Los Angeles, California October 10, 2014. (Photo by Lucy Nicholson/Reuters)

A competitor shows her tattoos at the MBK Tattoo Contest in a shopping mall in Bangkok October 23, 2014. (Photo by Athit Perawongmetha/Reuters)

A resident looks into a newly-built giant trash can, partially buried underground, next to a street in Taiyuan, Shanxi province November 6, 2014. The trash can, which has a diameter of 1.9 meters and a depth of 2.8 meters, could contain approximately 10 cubic metres of garbage. It was built to replace an open-air garbage dump site, local media reported. (Photo by Reuters/Stringer)

Fishermen prepare marlin and sailfish, destined for Jakarta, for auction at a fish market in Tegal, Central Java November 26, 2014 in this photo taken by Antara Foto. (Photo by Oky Lukmansyah/Reuters/Antara Foto)