An Indian labourer carries a sack of plastic bottles on his head near one of the largest disposal sites in north-east India, ahead of the “World Environment Day” in Boragaon area of Guwahati on June 4, 2018. World Environment Day is marked annually on June 5, and aims at promoting awareness and action to protect the environment. (Photo by Biju Boro/AFP Photo)

A police cadet casts her vote in the presidential election in Moscow, Russia, Sunday, March 18, 2018. Vladimir Putin headed to an overwhelming win in Russia' s presidential election Sunday, adding six years in the Kremlin for the man who has led the world' s largest country for all of the 21 st century. (Photo by Pavel Golovkin/AP Photo)

Two men using an electric power saw to fell a tree circa 1940's. (Photo by Keystone View/FPG/Getty Images)

Soldiers, including two recruits who have brought some chickens, at Victoria prepare to board the train for the battle front. (Photo by Hulton Archive/Getty Images)

Two young women embrace in bed together, both wearing white lace underwear. (Photo by Popperfoto/Getty Images)

Two cocks are trained for a fight in a village in Nakhon Sawan province, Thailand January 10, 2017. (Photo by Chaiwat Subprasom/Reuters)

Two zebras stand so close in Ngorongoro Crater, Tanzania. (Photo by Zhayynn James/Solent News)

Two sheep fight in a competition in Zhangjiakou, Hebei province, China on August 1, 2017. (Photo by Reuters/China Stringer Network)