Members of an American landing party assist troops whose landing craft was sunk by enemy fire off Omaha beach, near Colleville sur Mer, France, June 6, 1944. REUTERS/Weintraub/US National Archives

A man standing on the first cables during the construction of the Golden Gate Bridge with the Presidio and San Francisco in the background, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

American soldiers leaping from an armoured personnel carrier during exercises in Korea, 17th March 1954. (Photo by Three Lions)

Peru, Iquitos. Restaurant in Bellavista, an area by the Amazon on April 2005. (Photo by Jean-Claude Coutausse)

U.S. Rep Steve Southerland grins after winning an auctioned possum during the Wausau Possum Festival on Saturday, August 2, 2014, in Wausau, Fla. What is usually a must-attend event for statewide candidates was notably lacking of them this year, perhaps because candidates who now raise tens of millions of dollars focus more on television ads than making personal contact. But not attending is a missed opportunity, said Susan MacManus, a University of South Florida political science professor who drove more than 350 miles for the festival. (Photo by Heather Leiphart/AP Photo/The News Herald)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

Comic Con fans in costume arrive for the 2nd day of the 2016 New York Comic Con at the Jacob Javits Center on October 7, 2016. The four- day event which runs October 6-9 is the largest pop culture event on the East Coast. (Photo by Timothy A. Clary/AFP Photo)

Wakhi nomad women milk yaks in Wakhan, Afghanistan. About 12,000 villagers live at an altitude of 4,500 metres in the harsh, desolate terrain. The Wakhi people live a simple, relaxed life with their livestock. (Photo by Eric Lafforgue/Barcroft Images)