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

A visitor walks past an installation artwork entitled “Confuciuse” which combines the word “Confucius” and “confuse” in the contemporary art exhibition at “Fun and Art” Festival on December 13, 2008 in Xian of Shaanxi Province, China. (Photo by China Photos/Getty Images)

A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)

Artwork by Ruth Bellotti & Steve Rosewell called “Soldier Scale 1:1” is seen at the 2008 Sculpture by the Sea launch at Mark's Park, Bondi on October 15, 2008 in Sydney, Australia. (Photo by Gaye Gerard/Getty Images)

“Alan Alexander “A. A.” Milne (18 January 1882 – 31 January 1956) was an English author. Milne is most famous for his two Pooh books about a boy named Christopher Robin after his son, and various characters inspired by his son's stuffed animals, most notably the bear named Winnie-the-Pooh”. – Wikipedia

Photo: A rare American first edition of a Winnie-the-Pooh book signed by the author A.A. Milne and illustrator E. H. Shephard is displayed with Pooh characters form a 1930's game at a press preview at Sotheby's Auctioneers on December 15, 2008 in London. (Photo by Peter Macdiarmid/Getty Images)

Vendors sell clothes on the roadside at a second-hand street side clothing market in Mumbai January 28, 2015. The market is open daily for three hours and hundreds of vendors gather to barter or sell used clothing. (Photo by Danish Siddiqui/Reuters)

A woman cartwheels through the Coachella Valley Music and Arts Festival in Indio, California April 10, 2015. (Photo by Lucy Nicholson/Reuters)

A six-year-old acrobat performs on the opening of a tourist festival in Bozhou, Anhui province, China May 3, 2015. (Photo by Reuters/China Daily)