Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

Six year old Gillian Smith preparing for the All England Stage Dancing Competition where she has previously won five certificates and a silver medal in the under sevens category. (Photo by Terry Fincher/Keystone/Getty Images). 5th July 1957

A girl uses her mobile phone during the evening at the National Park in Khartoum, Sudan, April 24, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

Boys play with a drainage culvert used for flood control in Las Pinas, Metro Manila February 28, 2016. (Photo by Erik De Castro/Reuters)

US actress Alexandra Daddario attends the “Baywatch” Photo Call in Berlin on May 30, 2017 in Berlin, Germany. (Photo by Splash News and Pictures)

The BADGER shot was a 23 kiloton nuclear bomb. Over 2,000 US soldiers were within 3.7 kilometers of the explosion. (Photo by Alamy Stock Photo)

A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)