Tour guides wearing traditional Chinese dress practice smiling by biting chopsticks at Qingming Grand-River Park in Kaifeng, central China's Henan Province on March 2, 2017, aiming to provide better service for visitors. (Photo by IPA Asia via ZUMA Wire)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

A line of soldiers firing handguns during a training session, circa 1920. (Photo by Keystone). P.S. All pictures are presented in high resolution.

“«Pirate radio» in the UK first became widespread in the early 1960s when pop music stations such as Radio Caroline and Radio London started to broadcast on medium wave to the UK from offshore ships or disused sea forts. At the time these stations were not illegal because they were broadcasting from international waters. The stations were set up by entrepreneurs and music enthusiasts to meet the growing demand for pop and rock music, which was not catered for by the legal BBC Radio services”. – Wikipedia

Photo: The “World in Action” team making a program about the pirate radio ship Caroline, filmed by Paddy Searle, and produced by Mike Hodges. The DJ being filmed is Robbie Dale, and Hodges is standing behind him. (Photo by James Jackson/Evening Standard/Getty Images). 6th September 1967

Back in England, one of the British soldiers that continue to return in their thousands from Northern France, belies any mood of defeat with some high spirited piping on a train. (Photo by Parker/Fox Photos/Getty Images). 1st June 1940

US actress Zendaya arrives for the 45th annual E! People's Choice Awards at Barker Hangar in Santa Monica, California, on November 10, 2019. (Photo by Jean-Baptiste Lacroix/AFP Photo)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

A couple watches the sunset over a sea of fog covering the Geneva Lake from Chardonne, Switzerland, 28 December 2015. (Photo by Jean-Christophe Bott/EPA)