As an airliner prepares to land, a bird takes off at the Gravelly Point park near Reagan National Airport in Arlington, Va. on December 23, 2018. (Photo by Michael S. Williamson/The Washington Post)

A young female demonstrator is arrested by police during clashes in the Causeway Bay area of Hong Kong, China on October 6, 2019. Hundreds of thousands of protesters marched through the city's streets in defiance of the new “no-mask” law, which was introduced two days ago as demonstrations roll into a 14th week. (Photo by Rick Findler/EPA/EFE/Rex Features/Shutterstock)

An Algerian demonstrator wearing face paint in the colours of the national flag takes part in an anti-government demonstration in the capital Algiers on November 1, 2019. Demonstrators converged on Algiers in their thousands for a massive anti-government rally called to coincide with official celebrations of the anniversary of the war that won Algeria's independence from France. (Photo by Ryad Kramdi/AFP Photo)

Actress Ella Balinska attends a Charlie's Angels VIP Screening Hosted by Elizabeth Banks and Natalie Zfat, in Partnership with Harry & David at AMC Empire 25 on November 05, 2019 in New York City. (Photo by Ben Gabbe/Getty Images for Sony Pictures)

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)

Artists called “Le couple en chocolat” take part in the festival “Statues en Marche” in Marche-en-Famenne, Belgium, July 22, 2018. Living statues are a common sight in many city centres, but it is rare to see such a diverse range of this peculiar form of street art for which performers must keep still for painfully long periods of time to create the desired illusion. (Photo by Yves Herman/Reuters)

Climbers place a huge 80x80 metres (262x262 feet) Swiss national flag on the western face of the north-eastern Swiss landmark Mount Saentis, Switzerland on July 31, 2018. (Photo by Arnd Wiegmann/Reuters)

Democratic Congressional candidate Alexandria Ocasio-Cortez poses with a campaign worker during a whistle stop in Queens, New York, November 5, 2018. (Photo by Andrew Kelly/Reuters)