In this April 23, 2015 photo, friends Jia Haixia, left, and Jia Wenqi work to plant a tree in a field in Yeli village near Shijiazhuang city in northern China's Hebei province. For the past 13 years, Jia Wenqi, who has no arms, and Jia Haixia, who is blind, have worked together to plant and water more than 12,000 trees near their village. (Photo by Helene Franchineau/AP Photo)

Iranians flash the victory sign from their car while celebrating on a street in northern Tehran, Iran, Thursday, April 2, 2015, after Iran's nuclear agreement with world powers in Lausanne, Switzerland. The United States, Iran and five other world powers on Thursday announced an understanding outlining limits on Iran's nuclear program so it cannot lead to atomic weapons, directing negotiators toward achieving a comprehensive agreement within three months. (Photo by Ebrahim Noroozi/AP Photo)

Alee Harrison, 13, wears the tv series “Doctor Who” on her legs as she works on a painting for Operation Blue Pride. (Photo by Greg Lovett/The Palm Beach Post)

Jewels Lewis poses as the first customer to purchase the new Apple iPad 2 at Apple Store, Regent Street on March 25, 2011 in London, England. The latest iPad went on sale in the UK at 5:00pm.

Sheep are waiting in Via Manzoni before the final filming of the Last Shepherd on October 1, 2011 in Milan, Italy. Directed by Marco Bonfanti, L'Ultimo Pastore (The Last Shepherd) tells the story of the life of Renato Zucchelli, the last nomadic shepherd in Milan. (Photo by Pier Marco Tacca/Getty Images)

South Koreans wear Santa Claus outfits and hold gifts to promote Christmas at a charity event on December 23, 2011 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

A group of people wearing full solid-coloured bodysuits walk along a promenade as they take part in a street art performance in Bat Yam, near Tel Aviv, Israel August 29, 2015. Some 40 people participated on Saturday in the performance, initiated by a group of artists called Prizma Ensemble, as part of the city's annual international street art and street theatre festival. The group says the performance deals with concepts of identity and movement in public spaces. (Photo by Amir Cohen/Reuters)