A World War II era P-51 Mustang fighter plane stands in front of a modern 747-8 freighter and a 757 passenger jet at The Boeing Company's centennial celebration in Renton, Washington, U.S. July 15, 2016. (Photo by Alwyn Scott/Reuters)

A Colombian anti-narcotics policeman stands guard after burning a cocaine lab, which police said belongs to criminal gangs, in a rural area of Calamar in Guaviare state, Colombia, August 2, 2016. Colombian law enforcement has destroyed 104 cocaine laboratories capable of producing some 100 tonnes of the drug annually, the head of the anti-narcotics police said on Tuesday. (Photo by John Vizcaino/Reuters)

A Humboldt penguin stands on weighing scales whilst being photographed by members of the press during a photocall at the annual weigh-in at London Zoo in London, Britain, 24 August 2016. Every animal that is in the zoo is weighed and measured and the statistics recorded so the data can be shared with zoos across the world. (Photo by Hannah McKay/EPA)

A woman holds a parasol as she stands in a field of fireweed, or Kochia scoparia, on a sunny autumn day at the Hitachi Seaside Park in Hitachi, north of Tokyo, October 26, 2015. Fireweed is a grass bush that takes on a bright red colour in autumn. (Photo by Thomas Peter/Reuters)

1: Dubai's Burj Khalifa is the tallest building in the world, but perhaps not for long. Saudi Arabia has announced plans to build a 1 kilometer (3,280 foot) tower into the sky, to be named the Jeddah Tower, scheduled for completion in 2020. The Burj Khallifa currently stands at 2,716 ft. (Photo by Matthias Seifert/Reuters)

Boys dressed in historical uniforms stand before a military parade in Red Square in Moscow November 7, 2014. The parade marked the anniversary of the 1941 parade when Soviet soldiers marched through the Red Square towards the front lines of World War Two. (Photo by Maxim Shemetov/Reuters)

A man removes ice from an ice-covered car with a hammer in Postojna, Slovenia, on February 5, 2014. Cars stand entombed in a crystal-like casing near the deserted railway station in Postojna. Trees and electricity pylons lie felled in the snow by the sheer weight of ice enveloping them. (Photo by Srdjan Zivulovic/Reuters)

North Korean leader Kim Jong Un (front) stands on the conning tower of a submarine during his inspection of the Korean People's Army (KPA) Naval Unit 167 in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang June 16, 2014. (Photo by Reuters/KCNA)