A man carries a bag on his back in Guangzhou, Guangdong province, January 26, 2016. According to traffic police, over 2.9 billion trips will be made around China during the 40-day Spring Festival travel rush, which started on January 24. (Photo by Reuters/Stringer)

Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)

A man sits under lanterns and decorations on a street ahead of the Chinese Lunar New Year in Chinatown Yangon, Myanmar January 23, 2017. (Photo by Soe Zeya Tun/Reuters)

Cheerleaders let their hair fly as they perform prior to a German first division Bundesliga soccer match between 1. FC Cologne and Bayern Munich in Cologne, Germany, March 4, 2017. (Photo by Michael Probst/AP Photo)

The Pink Floyd inflatable pig floats next to Broadcasting House to promote their new exhibition at the V&A museum, in London, Britain May 10, 2017. (Photo by Neil Hall/Reuters)

Britain's Princess Elizabeth clasps her hands in sympathy as Sergeant Jean Bayliss faints at her feet during an inspection of the guard of honour of the Women's Royal Army Corps at Shrewsbury Castle, Shropshire, on July 6, 1949. (Photo by AP Photo)

A swimmer competes in Le Defi Monte-Cristo (Monte Cristo Challenge) swimming event at the Chateau d'If, off the coast of Marseille, southern France, on June 21, 2019. Created in 1999 and inspired by Alexandre Dumas' character of Edmond Dantes, the Monte Cristo Challenge will take place from June 21 to 23, 2019. (Photo by Boris Horvat/AFP Photo)

Clouds in Drakensberg Escarpment in the lowveld, also known as Mariepskop, South Africa in July 2019. Snapped by professional Photographer, Em Gatland, 37, from Greater Kruger, South Africa, the unique shot could easily be mistaken for a dangerous wave rather than clouds passing through a sunset. (Photo by Em Gatland/Caters News Agency)