Food is placed on the tomb of pet dog Xixi at Baifu pet cemetery ahead of the Qingming Festival on the outskirts of Beijing, China March 26, 2016. The Chinese characters on the gravestone read: “Mommy's only good son”. (Photo by Jason Lee/Reuters)

Two brown bear cubs born at Whipsnade Zoo. (Photo by Evening Standard/Getty Images). 1970

A Leyland lorry during the railway strike, “we supply both milk and baby” is chalked on the bonnet. (Photo by A. R. Coster/Topical Press Agency/Getty Images). 3rd October 1919

Terashima Takeshi and Akaishi Kazuya of Japan block a shot from Indonesia during day one of the ISTAF Super Series at Palembang Sport Convention Center on February 23, 2012 in Palembang, Sumatra, Indonesia. (Photo by Nicky Loh/Getty Images for UFA Sports)

Chinese special policemen rank in a line of battle during an anti-terror drill at a training base of Chengdu Armed Police Headquarters on September 28, 2005 in Chengdu of Sichuan Province, China. (Photo by China Photos/Getty Images)

Alphajet aircraft draw a heart-shaped message in the sky during the 2010 presentation show of the French aerobatics team Patrouille de France, over the French city of Salon-de-Provence. (Photo by Gerard Julien/AFP Photo)

Lucinda Grange perches on the eagle's head on the corner of New York's iconic Chrysler Building in Manhattan, New York City. (Photo by Lucinda Grange/Barcroft Media USA)

A street cleaner demonstrates his martial arts skills in front of a closed shop near Beijing's Tiananmen Square September 2, 2015 as the capital prepares for tomorrow's parade. (Photo by Damir Sagolj/Reuters)