Pilot Akmal Bin Abdul Kahar watches South Korea's Black Eagles aerobatics team perform a manoeuvre during an aerial display at the Singapore Airshow at Changi Exhibition Center February 18, 2016. (Photo by Edgar Su/Reuters)

Fireworks explode above Singapore's financial skyline at dusk as part of celebrations for the nation's 50th year of independence, Sunday, August 9, 2015, in Singapore. Singapore declared independence on August 9, 1965. (Photo by Wong Maye-E/AP Photo)

Girls take a selfie at the haze shrouded Batanghari River bridge in Jambi, Indonesia Sumatra island, September 14, 2015. Indonesian islands are blanketed in the so-called “haze”, caused by slash-and-burn clearances on the islands of Sumatra and Borneo, which makes thousands sick, delays flights and pushes air quality to unhealthy levels in neighboring Singapore and Malaysia. (Photo by Reuters/Beawiharta)

Commuters walk up the redesigned subway stairs at the Tanjong Pagar subway station on August 23, 2011 in Singapore. The subway stairs have been repainted in bright colours and slogans encouraging people to take the stairs, by way of promoting fitness in the city. (Photo by Chris McGrath/Getty Images)

Racing driver J. Gaal at the wheel of car number 26 at the RAC Tourist Trophy, run, for the first time, over the Four Inch Course on the Isle of Man, 17th September 1908. Gaal is racing in waterproofs. (Photo by Topical Press Agency/Hulton Archive/Getty Images)

Participants take part in an extreme run “Bison race” near the town of Logoisk, Belarus September 17, 2016. (Photo by Vasily Fedosenko/Reuters)

A participant competes in the “Farinato Race” winter extreme run competition in Gijon, northern Spain, January 31, 2016. (Photo by Eloy Alonso/Reuters)

Dustin Murley (L) and Jessey Sisson race on their ostriches during the annual Ostrich Festival in Chandler, Arizona March 10, 2013. (Photo by Joshua Lott/Reuters)