An undated archive picture shows a dog pulling a Belgian machine gun at an unknown location in northern France. A Viscount in the Armoured Cavalry Branch of the French Army left behind a collection of hundreds of glass plates taken during World War One (WWI) that have never before been published. The images, by an unknown photographer, show the daily life of soldiers in the trenches, destruction of towns and military leaders. The year 2014 marks the 100th anniversary of the start of WWI. (Photo by Collection Odette Carrez/Reuters)

A robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)

Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

British band Florence and the Machine performs at the Bilbao BBK Live festival in Bilbao, Spain, early 13 July 2018. Bilbao BBK Live festival runs from 12 July to 14 July 2018. (Photo by Miguel Tona/EPA/EFE)

A boy holds a machine gun at a military hardware exhibition during a swear-in ceremony for new recruits of the Russian military-patriotic club “Yunarmia” (Young army) in the Black Sea port of Sevastopol, Crimea, October 27, 2018. (Photo by Pavel Rebrov/Reuters)

Social activists working for the rights of sеx workers celebrate with colour powder during the International Sеx Workers' Rights Day in Kolkata on March 3, 2020. (Photo by Dibyangshu Sarkar/AFP Photo)

A sеx worker participates in a march to raise public awareness on human rights issues in their profession on International Day to End Violence Against Sеx Workers in Skopje, Macedonia December 17, 2016. (Photo by Ognen Teofilovski/Reuters)

A dejected German Grenadier carrying a machine gun on his shoulder in front of a building on fire during the German retreat in Russia. (Photo by Keystone/Getty Images). 1944