An Zi, is squashed amongst other commuters in a subway train on his way to work in Beijing, China, November 12, 2015. An, a movie producer, moved to Dongsanqi village in Changping this year. His commute to work can take about 2 hours, with transportation costs topping 200 yuan a month, or about a fifth of his monthly rent. (Photo by Jason Lee/Reuters)

A member of security personnel stands on duty on an empty train platform inside a station on the Subway Line Number 1 on the eve of the Chinese Lunar New Year, in Beijing, China, February 7, 2016. According to local media, traffic in Beijing has seen a rare relief from its usual heavy pressure after 15 million people have left the city, heading for family reunions in their hometowns on the eve of the Chinese Lunar New Year of Monkey. (Photo by Jason Lee/Reuters)

Promotional staff dressed in outfits of animation characters use a mobile phone at the Global Mobile Internet Conference (GMIC) 2015 in Beijing, China, April 28, 2015. (Photo by Kim Kyung-Hoon/Reuters)

Catherine, Duchess of Cambridge smiles as she is saluted to during the Irish Guards Medal Parade at the Victoria Barracks on June 25, 2011 in Windsor, England. The Duchess of Cambridge and Duke of Cambridge are at the barracks to present service medals to members of the Irish Guards. (Photo by Chris Jackson/Getty Images)

Members of the 3rd U.S. Infantry Regiment place American flags at the graves of U.S. soldiers buried at Arlington National Cemetery in preparation for Memorial Day May 26, 2011 in Arlington, Virginia. “Flags-In” has become an annual event since the 3rd U.S. Infantry Regiment (The Old Guard) was appointed an Army official ceremonial unit in 1948. Every available soldier in the 3rd U.S. Infantry Regiment participates in these annual ceremonies. (Photo by Win McNamee/Getty Images)

Participants run at the “Half-Naked Marathon” at Olympic Forest park in Beijing, China, February 28, 2016. This annual running event which requires participants to run half-naked, was organized to promote environmentally friendly lifestyles. (Photo by Kim Kyung-Hoon/Reuters)

Lance Sergent Martin Mitchell (R) pins medals to Coldstream Guardsman Martin Hughes in the Tailor Shop in Wellington Barracks on April 20, 2011 in London, England. Soldiers involved in the Royal Wedding of Prince William and Catherine Middleton are preparing their ceremonial duties ahead of the day. (Photo by Oli Scarff/Getty Images)

A vehicle is trapped in a flooded street during a rainstorm in Beijing city on June 23, 2011 in Beijing, China. Heavy rain that hit Beijing on Thursday afternoon has disrupted traffic and caused flooding low-lying areas. (Photo by ChinaFotoPress/Getty Images)