Spectators dressed as leprechauns attend St Patrick's Day parade in Dublin on March 17, 2014. (Photo by Peter Muhly/AFP Photo)

Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

Pionneers from Aubagne's 1st Foreign Regiment (Legion etrangere) march the Champs-Elysees during the annual Bastille day parade on July 14, 2011 in Paris, France. The French National Day celebrates its revolution in the storming of the Bastille in 1789 through various parades and official ceremonies throughout France. (Photo by Franck Prevel/Getty Images)

Lamas dance during the “Tiaoqian” praying ceremony at the Youning Temple on February 8, 2009 in Huzhu County of Qinghai Province, China. (Photo by China Photos/Getty Images)

A model walks down the runway at the 13th China International Young Fashion Designers Contest during China Fashion Week on March 25, 2005 in Beijing, China. (Photo by China Photos/Getty Images)

A dog from the K9 Division of the Sri Lanka Army’s Commando Regiment performs during an event to mark International Children’s Day at a school in Welisara, Colombo, Sri Lanka, 01 October 2016. Sri Lanka marks the Children's Day on 01 October with more emphasis on prevention of child abuse. (Photo by M.A. Pushpa Kumara/EPA)

Competitors gather backstage as they prepare to take part in the All Ireland Irish Dancing Championships on November 2, 2016 in Belfast, Northern Ireland. The championships take place at the Waterfront Hall over the course of six days with winners qualifying for the World Irish Dancing Finals which will take place in Dublin next year. (Photo by Charles McQuillan/Getty Images)

A boy poses for a photo as he plays with a homemade toy gun in Qayara, south of Mosul, Iraq, Tuesday, November 22, 2016. For months, residents of the Iraqi town of Qayara have lived in the darkness from a cloud of toxic fumes released by oil fields lit by retreating Islamic State fighters. (Photo by Felipe Dana/AP Photo)