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)

Drivers push cars to gas station during “oil crisis”, Roslindale, Boston, Massachusetts, 1973. (Photo by Spencer Grant/Getty Images)

Women walk past a mannequin with a covered face as they shop ahead of the Muslim festival of Eid-al-Adha in Aleppo, Syria September 23, 2015. (Photo by Hamid Khatib/Reuters)

Children in a Hong Kong refugee resettlement area watch as former Vice President Richard Nixon shows them his badminton service. Nixon visited Hong Kong, April 4, 1964, during his tour of countries in the Far East. (Photo by AP Photo)

Members of the San Francisco Gay Freedom Day Marching Band and Twirling Corps do their thing down San Francisco's Market Street, June 27, 1982. Police estimate the crowd to be 300,000 for the Lesbian/Gay Freedom Day parade and rally. (Photo by Carl Viti/AP Photo)

American actress Raquel Welch on a balcony overlooking a street in London, 1970. (Photo by Evening Standard). P.S. All pictures are presented in high resolution.

Three members of English pop group The Tremeloes; Chip Hawkes, Alan Blakley and Dave Munden, kissing their brides; Carol Dilworth, Lyn Stevens and Andree Wittenberg, in Trafalgar Square, London. (Photo by Wesley/Getty Images). 1967

A Colombian soldier hugs his girlfriend during the graduation ceremony of soldiers in Nilo, Colombia, February 17, 2017. The soldiers will be deployed to occupy territories formerly controlled by FARC rebels. (Photo by Jaime Saldarriaga/Reuters)