Young children at a Bristol, Great Britain health centre unsure of the benefits of sun-lamps and the special glasses that must be worn, July 1948. The health centre was part of the newly introduced free National Health Service. (Photo by Popperfoto/Getty Images)

An opposition fighter from the Failaq al-Rahman brigade fires a heavy machine gun in Jobar, a rebel-held district on the eastern outskirts of the Syrian capital Damascus, on March 19, 2017. (Photo by Amer Almohibany/AFP Photo)

A woman walks past servicemen of the self-proclaimed Donetsk People's Republic (DNR), who take part in a rehearsal for the Victory Day parade in Donetsk, Ukraine on May 3, 2018. (Photo by Alexander Ermochenko/Reuters)

In this January 11, 2017 photo, Erika Martins uses black electrical tape to create a customer's bikini, in order to attain crisp tan lines, on her rooftop Erika Bronze salon in the suburb of Realengo in Rio de Janeiro, Brazil. Martins wears a microphone connected to an open speaker system in order to direct her assistants to clients who need more tanning lotion or a sprinkling of water on their skin. (Photo by Renata Brito/AP Photo)

An Israeli Air Force F-35 fighter jet flies during an aerial demonstration at a graduation ceremony for Israeli airforce pilots at the Hatzerim air base in southern Israel December 29, 2016. (Photo by Amir Cohen/Reuters)

Couples take part in a competition during a mass wedding of 64 doctoral student couples at Harbin Institute of Technology, a university in Harbin, Heilongjiang province, China, June 4, 2017. (Photo by Reuters/Stringer)

This screengrab from Thai TV Pool video taken on May 1, 2019 shows a ceremony in which Thailand's King Maha Vajiralongkorn “legally married” Suthida Vajiralongkorn na Ayudhya in Bangkok. Thailand announced on May 1, 2019 that King Maha Vajiralongkorn's long-time consort had become his fourth wife, bestowed with the title Queen Suthida – a surprise move just days before his coronation. (Photo by Bureau of the Royal Household via Reuters)

A woman affected by tear gas is assisted during a May Day protest against austerity measures, in San Juan, Puerto Rico May 1, 2018. (Photo by Alvin Baez/Reuters)