A Chesterfield Borough Police telephone operator tests a gasmask with built in earpiece and microphone. The telephone service is considered one of the most important links in the coordination of ARP operations and must remain operational during air raids, 12th April 1939. (Photo by Fox Photos/Hulton Archive/Getty Images)

Dead leaf or almost by Guilhem Duvot. Taken in Nován Stráž, Slovakia. Describe what is pictured? A dead leaf grasshopper. How does this image fit with the theme of the competition? The perfect camouflage – nature is amazing. I saw the grasshopper only because it jumped. (Photo by Guilhem Duvot/Royal Society of Biology)

A picture taken with a drone shows the giant landart painting entitled “Message From Future” by French artist Saype in the park “La Perle du Lac” in Geneva, Switzerland, 16 September 2018 (issued 17 September). The artwork covering 5,000 square meters was produced with biodegradable paints made from natural pigments. The artist called the little girl “Future” as a symbol of the generations from the future and the small origami boats that she drops into Lake Geneva aims to represent a message of hope sent to the world. (Photo by Valentin Flauraud/EPA/EFE)

Members of the China Disabled People’s Performing Art Troupe take part in the thousand-hand Bodhisattva dance in Mississauga, Canada on November 8, 2018. (Photo by Zou Zheng/Xinhua News Agency/Barcroft Images)

Paolo Guerrero of Brazil's Internacional reacts after missing an opportunity to score during a Copa Libertadores soccer match against Chile's Palestino in Porto Alegre, Brazil, Tuesday, April 9, 2019. (Photo by Diego Vara/Reuters)

Swiss grass skier Stefan Portmann in action during a free practice at the Grasski World Championships in Marbach, Switzerland, 13 August 2019. About 80 participants from 10 nations will start at the Grasski - World Championships, which will take place from 13th to 18th August 2019. (Photo by Alexandra Wey/EPA/EFE)

US actress Jennifer Lawrence signs autographs before the premiere of the movie “Mother” presented in competition at the 74 th Venice Film Festival on September 5, 2017 at Venice Lido. (Photo by Tiziana Fabi/AFP Photo)

Smoke and flames rise over a warehouse storing ammunition for multiple rocket launcher systems at a military base in the town of Kalynivka in Vinnytsia region, Ukraine September 27, 2017. Ukrainian officials say they have evacuated more than 30,000 people after a fire and ammunition explosions, at the military base on Tuesday. (Photo by Gleb Garanich/Reuters)