Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)

An Armatix employee holds a “smart gun” by the company at the Armatix headquarters in Munich May 14, 2014. The gun is implanted with an electronic chip that allows it to be fired only if the shooter is wearing a watch that communicates with it through a radio signal. If the gun is moved more than 10 inches (25 cm) from the watch, it will not fire. A Maryland gun shop owner has dropped his plan to be the first in the United States to sell the so-called “smart gun” after a backlash that included death threats. (Photo by Michael Dalder/Reuters)

A reveller holds a sign reading “2020BYE” as a small number of people begin celebrating New Year's Eve at the Sydney Harbour waterfront amidst tightened COVID-19 regulations in Sydney, Australia, December 31, 2020. (Photo by Loren Elliott/Reuters)

North Korean leader Kim Jong Un smiles as he attends a flight training session by female fighter pilots Jo Kum Hyang and Rim Sol in this undated photo released by North Korea's Korean Central News Agency (KCNA) on June 22, 2015. (Photo by Reuters/KCNA/Antara Foto)

A woman walks against blowing snow in Evanston, Illinois, on February 8, 2014. (Photo by Nam Y. Huh/Associated Press)

Law enforcement officers stand, with some turning their backs, as New York City Mayor Bill de Blasio speaks on a monitor outside the funeral for NYPD officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Tens of thousands of law enforcement officers from across the country gathered on Sunday for the funeral of the second of two New York City policemen killed last month in an ambush that galvanized critics of Mayor de Blasio. (Photo by Shannon Stapleton/Reuters)

Three cabaret dancers sit glum-faced in the Windmill Theatre's canteen upon hearing the news that the theatre's owners have sold out to a cinema company, on October 02, 1964. The theatre, which was the first to include nudity in its shows, has been able to cope with competition from a growing number of West End strip clubs. (Photo by Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images)

A spectator at the Maslenitsa car battle, reacts during a clash, in the village of Goroshki, some 35 kilometers from Minsk, Belarus, 12 March 2016. The battle which is held at the Historical and Cultural Complex, Stalin line, is a small local competition, with participants from Belarus and Russia. (Photo by Tatyana Zenkovich/EPA)