Two traditional folk dancers performing in Teheran, Iran. (Photo by Keystone Features/Getty Images). 25th January 1961

Two sailors from HMS Fury enjoy a smoke with two women in bathing suits on a beach in Jersey, where their ship is on a visit. (Photo by William Vanderson/Fox Photos/Getty Images). 29th June 1935

Two elderly men smoking pipes of opium on a terrace in Korea. (Photo by Bert Hardy/Picture Post/Getty Images). August 1950

Two cats watch a mouse walking on the pavement in Kuwait City on March 8,2017. (Photo by Yasser Al-Zayyat/AFP Photo)

Two couples prepare to pose for their wedding pictures outside the Forbidden City in Beijing on October 31, 2022. (Photo by Wang Zhao/AFP Photo)

Two Bulgarian tourists pose in front of the Eiffel Tower in Paris on their last day in the capital on March 24, 2014. (Photo by Franck Fife/AFP Photo)

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)

An iCub robot built by the Italian Institute of Technology tracks a ball in the Robotville exhibition at the Science Museum on November 29, 2011 in London, England. The Science Museum's Robotville exhibition showcases 20 unique and cutting-edge robots from European research laboratories, it is free to enter and runs from December 1–4, 2011. (Photo by Oli Scarff/Getty Images)