Dancers from Xinjiang delegation perform during the Opening Ceremony for the 9th National Traditional Games of Ethnic Minorities of the People's Republic of China on September 10, 2011 in Guiyang, China. (Photo by Feng Li/Getty Images)

Female panda Tian Tian makes her first appearance in front of the media since arriving from China on December 12, 2011 in Edinburgh, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

In this April 23, 2015 photo, friends Jia Haixia, left, and Jia Wenqi work to plant a tree in a field in Yeli village near Shijiazhuang city in northern China's Hebei province. For the past 13 years, Jia Wenqi, who has no arms, and Jia Haixia, who is blind, have worked together to plant and water more than 12,000 trees near their village. (Photo by Helene Franchineau/AP Photo)

A model showcases designs on the runway at MGPIN 2015 Mao Geping Makeup Trends Launch show during Mercedes-Benz China Fashion Week Spring/Summer 2015 at Beijing Hotel on October 27, 2014 in Beijing, China. (Photo by Feng Li/Getty Images)

Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

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

Bathing suit models are shown listening to the radio on the beach, circa 1940's. (Photo by Bettmann Archive/Getty Images)

Guests on the terrace of Shepheard's Hotel, Cairo, circa 1940. (Photo by Hulton Archive/Getty Images)