A guest proposes to his companion as they arrive for the screening of “Mektoub, My Love: Intermezzo” during the 72nd annual Cannes Film Festival, in Cannes, France, 23 May 2019. The movie is presented in the Official Competition of the festival which runs from 14 to 25 May. (Photo by Julien Warnand/EPA/EFE)

An aircraft crosses a bridge over a highway the airport in Frankfurt, Germany, Friday, September 20, 2019. Protests of the “Friday For Futurte” movement against the increase of carbon dioxide emissions are planned Friday in cities around the globe. In the United States more than 800 events were planned Friday, while in Germany more than 400 rallies are expected. (Photo by Michael Probst/AP Photo)

The full moon rises behind the cooling towers of the nuclear power station in Philippsburg, Germany, 06 May 2020. The nuclear power plant in Philippsburg was completely shut down by 31 December 2019. According to the operator EnBW, the two cooling towers are expected to be demolished by blasting on 14-15 May 2020. (Photo by Ronald Wittek/EPA/EFE)

Malian workers haul out a boat they use to carry sand collected from the river bed during a routine maintenance on October 7, 2018, in the port of Bamako. Increasing construction in the Malian capital has boosted the demand for bricks made out of high-quality Niger River sand. (Photo by Michele Cattani/AFP Photo)

A winter swimmer, wearing a Santa Claus hat to celebrate the upcoming Christmas, reacts as he plays on a frozen lake at a park in Shenyang, Liaoning province, December 22, 2014. The characters on the hat read: “Shenyang Winter Swimming”. (Photo by Reuters/Stringer)

A group of costumed fans attend Comic-Con International at San Diego Convention Center on July 12, 2015 in San Diego, California. (Photo by Daniel Knighton/Getty Images)

Female members of the Chinese People's Liberation Army (PLA) honour guard stand behind a string to ensure that they are in a straight line before a welcoming ceremony for Russian President Vladimir Putin outside the Great Hall of the People in Beijing, China, June 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

Artists perform during the Closing Ceremony of the Rio 2016 Olympic Games at the Maracana Stadium in Rio de Janeiro, Brazil, 21 August 2016. (Photo by Sergei Ilnitsky/EPA)