Fifty years ago, as France exploded in mass protests, words scrawled on the walls of the Sorbonne summed up the revolutionary zeal of the time: “Run free, comrade, we’ve left the old world behind!”. Sexual liberation, artistic creativity and anti-capitalism were the order of the day. For those who were there, it was an unforgettable time. Here: A wounded student is transported by first-aid workers during riots on the Boulevard Saint-Michel, Paris, France on May 6, 1968. (Photo by Gökşin Sipahioğlu/SIPA Press)

Vehicles pass through the heavy fog and air pollution that cover Skopje valley in the early morning, in Skopje, The Former Yugoslav Republic of Macedonia, 14 December 2017. According to media reports, Skopje is considered one of the most polluted cities in the world. (Photo by Georgi Licovski/EPA/EFE)

Belle Hassan is seen attending Lipstick and Champagne – party at STK on August 29, 2019 in London, England. (Photo by Jamie Lorriman/The Sun)

A 180 degrees rotated photograph shows the shadows of Polina (L), a six-year-old Belarusian first grade school girl, and her father, cast on the street while on their way to Polina's first day of school, which marks the traditional start of the academic year, in Minsk, Belarus, 02 September 2019. The start of a new academic year in Belarus, officially called Day of Knowledge, is a festive day for all school and university students in the country. (Photo by Tatyana Zenkovich/EPA/EFE)

A model presents a creation at a metro station during a show opening the Moscow Fashion Week in Moscow, Russia on October 22, 2019. (Photo by Evgenia Novozhenina/Reuters)

Festive decorations and illumination lights for the upcoming New Year and Christmas season are unveiled in Minsk, Belarus on December 15 , 2019. (Photo by Vasily Fedosenko/Reuters)

A Humboldt penguin swims in a pool during the annual stock take at ZSL London Zoo in London, Thursday, January 2, 2020. Caring for more than 500 different species, ZSL London Zoo's keepers face the challenging task of tallying up every animal large and small, every mammal, bird, reptile, fish and invertebrate at the Zoo. (Photo by Frank Augstein/AP Photo)

A riot policeman fires into the air during clashes with opposition supporters at a rally demanding a referendum to remove President Nicolas Maduro in Caracas, Venezuela, May 11, 2016. (Photo by Carlos Garcia Rawlins/Reuters)