Members of Japan's idol group “Virtual Currency Girls” wearing cryptocurrency-themed masks perform in their debut stage in Tokyo, Japan, January 12, 2018. Japanese female idols have teamed up to form the ‘Virtual Currency Girls’ group to promote the knowledge of cryptocurrencies through entertainment. Each of its 8 members represents a cryptocurrency: bitcoin cash, bitcoin, ether, neo, nem, ripple, mona, and cardano. (Photo by Kim Kyung-Hoon/Reuters)

Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

Rapper Future attends his “Future City” Birthday Party at Magic City on November 20, 2018 in Atlanta, Georgia. (Photo by Prince Williams/Wireimage)

Japanese hairdresser Megumi Takeichi cuts patterns into the hair of a camel ahead of the Bikaner Camel Festival in Bikaner in the western Indian state of Rajasthan on January 10, 2019. (Photo by Dinesh Gupta/AFP Photo)

Plaster cast moulds of victims of the Mount Vesuvius eruption lie on a display table in a laboratory at Pompeii October 13, 2015. An expert team made up of archaeologists, radiologists, orthodontists and anthropologists began on September 2015 to use CAT scan technology (computerised axial tomography) to peer inside the plaster cast moulds of Pompeii's victims, in a study that has added more detail to previous findings. A 16-layer scan had to be used in order to penetrate the hardened plaster but the results showed up impressive skeletal remains and near perfect teeth. (Photo by Alessandro Bianchi/Reuters)

Gymnast Ahmad al-Sawas performs gymnastic moves near damaged buildings in the rebel-held Bustan al-Qasr neighbourhood of Aleppo, Syria March 26, 2016. As Syrian gymnast Ahmad al-Sawas watched his country fall apart, his Olympic dream collapsed too. The last national champion before the fighting began, he knew that supporting the anti-government side in the five-year-old civil war would prevent him from being selected for the Rio Games. (Photo by Abdalrhman Ismail/Reuters)

A visitor and autumn foliage are reflected in the lake at Stourhead gardens in Wiltshire, Britain, November 2, 2018. (Photo by Toby Melville/Reuters)

Volunteers of a Wild Nature Preservation center release a group of owl chicks from the Toro Mountain in Menorca, Balearic Islands, Spain, 31 July 2019. (Photo by David Arquimbau Sintes/EPA/EFE/Rex Features/Shutterstock)