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)

Nguyen Manh Quan (top), 26, a civil servant, carries a girl using his throat area as he performs during a showcase of the traditional Thien Mon Dao kung fu at Du Xa Thuong village, southeast of Hanoi, Vietnam May 10, 2015. Thien Mon Dao, a traditional Vietnamese martial art, was formed by 18th century villagers in Du Xa Thuong village, who believed the art form could help improve health as well as fight against foreign invaders. There are currently about 3,000 practitioners including farmers, industry workers and state servants. These practitioners say they are able to bend metal against their bodies and carry heavy objects using their throats, eyes or tongues, as well as run across the surface of a river, according to Thien Mon Dao kung fu master Nguyen Khac Phan. (Photo by Reuters/Kham)

Faces adorn crosses placed in the Garden of Remembrance of some of Britain's armed forces members who have died in Afghanistan in the Garden of Remembrance outside Westminster Abbey at the official opening of the Royal British Legion's Field of Remembrance on November 5, 2009 in London, England. (Photo by Alastair Grant-Pool/Getty Images)

An Islamic religious leader and rebel supporter (R) chant to rally rebel fighters awaiting a rumored Libyan Army advance April 11, 2011 between the crucial towns of Ajdabiyah and Brega, Libya. Rebels continued to hold the strategic town of Ajdabiyah a day after NATO air power struck army troops loyal to Libyan ruler Moammar Gaddafi nearby, helping the rebels secure the city. (Photo by Chris Hondros/Getty Images)

A model walks the runway at the Dolores Cortes swim show during Mercedes-Benz Fashion Week Swim 2012 at The Raleigh on July 16, 2011 in Miami Beach, Florida. (Photo by Frazer Harrison/Getty Images for Dolores Cortes)