Radio City Music Hall Rockettes perform after days of rehearsal and routine polished to perfection at the Radio City Music Hall in New York City on July 26, 1949. (Photo by Ivan Dmitri/Getty Images)

Palestinian boy Mohammad al-Bana, 10, sells mints at a market in Gaza City March 29, 2016. Bana, whose father is unemployed, earns around 10 Shekels ($2.5) per day. The boy starts working after finishing school. He hopes to continue education and become an engineer in the future. (Photo by Mohammed Salem/Reuters)

In this Friday, March 13, 2015, Mitch Seavey's lead dogs with frosty whiskers at the Huslia, Alaska, checkpoint for the Iditarod Trail Sled Dog Race. (Photo by Loren Holmes/AP Photo/Alaska Dispatch News)

A devotee takes a holy bath at the Balaju Baise Dhara (22 water spouts) during the Baishak Asnan festival in Kathmandu April 4, 2015. Devotees believe that the water from these stone spouts, which is collected from the catchment area of the Nagarjun forest behind the spouts, will cure pains and skin diseases. (Photo by Navesh Chitrakar/Reuters)

Mongolian herder, Khurelsukh, throws the carcass of a goat onto a heap as he struggles to deal with losing a quarter of his herd, on March 8, 2010 in Bayantsogt, Tuv province, Mongolia. (Photo by Paula Bronstein /Getty Images)

South Korean police officers show their martial arts' skills during the official launch ceremony of the 2012 Seoul Nuclear Security Summit on February 15, 2012 in Seoul, South Korea. The Korean National Police Agency launched a security squad, exclusively established for the successful hosting of the 2012 Seoul Nuclear Security Summit. The 2012 Seoul Nuclear Security Summit will be held in Seoul from March 26-27, 2012. (Photo by Chung Sung-Jun/Getty Images)

A murmuration of migrating starlings is seen across the sky in southern Israel December 31, 2015. (Photo by Amir Cohen/Reuters)

Assam's Veerangana commandos take part in a rehearsal for India's Republic Day parade at Khanapara in Guwahati, India January 23, 2017. India celebrates its annual Republic Day on January 26. (Photo by Anuwar Hazarika/Reuters)