The crowd watches as stunt pilots Melissa Pemberton, Jurgis Kairys and Skip Stewart of The Immortals fly past pyrotechnics as they perform at The Australian International Airshow on March 1, 2015 in Avalon, Australia. (Photo by Scott E. Barbour/Getty Images)

Children of Indian laborers play on make-shift swings in Amritsar, India, May 12, 2015. (Photo by Narinder Nanu/AFP Photo)

People cool off in a fountain outside the Southbank Centre on June 30, 2015 in London, England. The UK is currently experiencing a heatwave, with temperatures of 35 degree celsius forecast tomorrow in some parts of the country. The extreme heat has already seen train cancellations and a health warning has been issued. (Photo by Rob Stothard/Getty Images)

A Sri Lankan elephant, accompanied by his mahout, browse through a roadside fruit stall in Colombo on January 19, 2015. The Sri Lankan elephant is listed as endangered by the International Union for Conservation of Nature (IUCN) as the population has declined by at least 50 percent over the last three generations, with the species threatened by habitat loss, degradation and fragmentation. (Photo by Lakruwan Wanniarachchi/AFP Photo)

A pro-Russian activist aims a pistol at supporters of the Kiev government during clashes in the streets of Odessa May 2, 2014. Police said a man was shot dead in clashes between a crowd backing Kiev and pro-Russian activists in the largely Russian-speaking southern port of Odessa, which lies west of Crimea, annexed by Moscow in March. (Photo by Yevgeny Volokin/Reuters)

A giant ham bread, a typical Venezuelan Christmas dish, is seen on a table during an attempt to break the Guinness World Record for the biggest ham bread, in Caracas November 15, 2014. The giant hallaca more than 120 metres long. (Photo by Carlos Garcia Rawlins/Reuters)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)