Furniture design “Chair” by Allen Jones ( £600,000-800,000) is seen at Christie's London on September 29, 2017 in London, England. Christie's Auction House is to sell millions of pounds worth of art and design from the 20th and 21st centuries during Frieze Week from October 3rd to October 7th. (Photo by Nils Jorgensen/Rex Features/Shutterstock)

People dance in a park on a foggy day in Huai'an, Jiangsu province, China October 10, 2017. (Photo by Reuters/China Stringer Network)

Leslie Cliff and his wife Violet, English figure skating pair. Olympic games of Garmisch-Partenkirchen (Germany), 1936. (Photo by Roger Viollet Collection/Getty Images)

Hotel ushers pose for a photo at Tiananmen Square as delegates attend the second plenary session of the National People's Congress (NPC) in Beijing, China, March 9, 2018. The CPPCC is the top advisory body of the Chinese political system and runs alongside the annual plenary meetings of the 13th National People's Congress (NPC), together known as “Lianghui” or “Two Meetings”. (Photo by Jason Lee/Reuters)

A participant poses for a photograph at the annual Easter Parade and Bonnet Festival in the Manhattan borough of New York City, New York, U.S. on April 1, 2018. (Photo by Gaia Squarci/Reuters)

Jackie Barajas of Chula Vista dressed as Loki at Comic-Con in San Diego, USA on July 22, 2017. (Photo by K.C. Alfred/San Diego Union-Tribune via ZUMA Press/Rex Features/Shutterstock)

Gunfire was brought to the steps of President Truman's Washington home, Blair House, as two assassins tried to kill the chief executive, November 1, 1950. One of the gunmen, Oscar Collazzo of New York, lay wounded at the bottom of Blair House's front steps after the president's police guard had finished their work, at the cost of one guards' life, Dec. 9, 1950. The second gunman was killed. (Photo by Harvey Georges/AP Photo)

The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)