A competitor walks on tightrope during a performance in Taizhou, Zhejiang Province, China, May 7, 2016. (Photo by Reuters/China Daily)

A tattoo artist applying ink on a girl's thigh at the 2016 Italian Tattoo Artists at the Palavela on September 17, 2016 in Turin, Italy. (Photo by Stefano Guidi/ZUMA Press/Splash News)

in Qayyarah, about 31 miles (50 km) south of Mosul, Iraq, Sunday, October 23, 2016.in Qayyarah, some 50 kilometers south of Mosul, Iraq, Sunday, Oct. 23, 2016. Islamic State fighters torched a sulfur plant south of Mosul, sending a cloud of toxic fumes into the air that mingled with oil wells the militants had lit on fire to create a smoke screen. (Photo by Marko Drobnjakovic/AP Photo)

French firemen wearing chemical protective suits take part in a mock chemical attack exercise at the Geoffroy Guichard stadium in Saint-Etienne, France, April 4, 2016 in preparation of security measures for the UEFA 2016 European Championship. (Photo by Robert Pratta/Reuters)

Miesha Tate, UFC women's bantaweight shows the media how to fight during a UFC press conference at Akasaka Garden City on August 26, 2014 in Tokyo, Japan. (Photo by Atsushi Tomura/Getty Images)

Accused Nazi criminal John Demjanjuk wears sunglasses as he arrives for his trial at a court room prior to the assumed verdict on May 12, 2011 in Munich, Germany. (Photo by Johannes Simon/Getty Images)

The Flying Bull's P-38 Lockheed Lightning N25Y / 13 – Red Bull – Flying Legends Airshow 2012 Duxford (Photo by Rob Lovesey)

A German rifleman beside the corpse of a French soldier in a trench at Fort Vaux, France, 1916. (Photo by Hulton Archive/Getty Images)