A boy sits on his father's shoulders to look at strawberries at the 7th International Strawberry Symposium on February 18, 2012 in Beijing, China. (Photo by Lintao Zhang/Getty Images)

A model presents a hairstyle during the 7th international festival of hairdressing art, fashion and design called “Crystal Angel” in Kiev, Ukraine, on April 18, 2013. (Photo by Gleb Garanich/Reuters)

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)

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)

This picture taken on February 23, 2014 shows participants wearing dresses running half-naked in the annual 3.5 km Undie Run held in the Olympic Forest Park smog-covered Beijing. Some 200 participants took part in this event, many of them with gas masks, as dangerous smog blighted swathes of northern China in recent days. (Photo by AFP Photo/STR)

A pair of giant pandas play in their enclosure at the Beijing Zoo on June 5, 2012 in Beijing, China. With an estimated 1,600 living in the wild, the endangered giant panda dwell in a few mountain ranges in central China, in Sichuan, Shaanxi, and Gansu provinces. (Photo by Lintao Zhang)