A girl attends Friday prayers in front of an army tank in Tahrir Square in Cairo February 18, 2011. Five years ago thousands of protesters took to the streets demanding the end of the 30-year reign of President Mubarak as Egypt became the second country to join the Arab Spring. After weeks of clashes, strikes and protests across Egypt, Mubarak resigned on February 11, 2011. (Photo by Suhaib Salem/Reuters)

Imogen Bankier of Scotland (L) and Chris Adcock of England in action during their round one mixed doubles match in the Yonex All England Badminton Open Championship on March 9, 2011 in Birmingham, England.

Zhang Ze of China in action during his Oceania zone group1 match against Bernard Tomic of Australia of the 2011 Davis Cup on July 8, 2011 in Beijing, China. (Photo by Lintao Zhang/Getty Images)

Girls sits on a bench during summer at the Central Park in New York, United States, 2011. (Photo by An Rong Xu)

A woman walks in central Rason city, northeast of Pyongyang, August 29, 2011. (Photo by Carlos Barria/Reuters)

Nekama, a baby North Chinese leopard, emerges from a basket at her official presentation to the media at Tierpark zoo on March 15, 2011 in Berlin, Germany. Nekama was born on January 7, 2011 and currently weighs 4.5 kg.