Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)

North Korean women soldiers take part in a military parade Saturday, April 15, 2017, in Pyongyang, North Korea, to celebrate the 105th birth anniversary of Kim Il Sung, the country's late founder and grandfather of current ruler Kim Jong Un. (Photo by Wong Maye-E/AP Photo)

Two people sit in an ambulance waiting to be treated after a Grad rocket slammed into a shopping mall in Donetsk's Kubishevski district, in the eastern Ukraine, on October 8, 2014. At least two people were killed, and five were injured after some six Grad rockets hit the area. (Photo by John Macdougall/AFP Photo)

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)

Live octopus is a delicacy in South Korea but is a known choking hazard, since the still-moving suction cups can cause tentacle pieces to stick in a person's throat. A baby octopus is often consumed whole, while larger varieties are cut up and the still-wriggling tentacles eaten with a splash of sesame oil. Photo: A South Korean man and a woman eat a live octopus during an event to promote a local food festival in Seoul on September 12, 2013. (Photo by Jung Yeon-Je/AFP Photo)

A woman looks at a swimmer getting herself warm after the annual Christmas winter swimming competition in the Vltava river in Prague December 26, 2014. (Photo by David W. Cerny/Reuters)

Infantrymen of the US First Army shake hands with Russian soldiers on the broken bridge over the Elbe after the link-up at Torgau, Germany. The US soldiers are (L-R): Pfc. John A Metzger, Delbert E Philpott, and Pvt. Thomas B Summers; all are from A Company, 271st Regiment. (Photo by Allan Jackson/Getty Images). 04-1945

British soldiers inspect a captured German place in the Horseguards' Parade, London during World War I in November 1914, with the London Eye in the background as a reminder of just how much has changed in the last 100 years. (Photo by Peter Macdiarmid/Getty Images)