Soldier boys at Fort Dix, N.J., learn something about guns during their working hours, as they show their girlfriends at a camp dance, December 13, 1940. In front row, playing with the coin amusement gun, from left: Pvt. Tom D'Amato of West Orange; Rose Sinkewicz, behind gun site, of Trenton; Julia Ivans of Trenton, and Pvt. Vernon Landers of Kearney. Back row: Pvts. William Sargent and William Corlies of Philadelphia. (Photo by AP Photo)

An Airbus A400M military aircraft lands at the ILA Berlin Air Show in Schoenefeld, south of Berlin, Germany, June 1, 2016. The Aerospace Exhibition at Schoenefeld Airport near Berlin takes place from June 1 till 4. (Photo by Fabrizio Bensch/Reuters)

Lourdes Maria Ciccone Leon walks the runway for Gypsy Sport show during New York Fashion Week on September 12, 2018 in New York City. (Photo by Splash News and Pictures)

Women practice yoga at a lotus pond in Tiande Lake on the International Yoga Day on June 21, 2017 in Taizhou, Jiangsu Province of China. (Photo by VCG/VCG via Getty Images)

An Indonesian jockey rides two bulls with a cart during a traditional sport bull race locally called “pacu jawi” in Pariangan of Tanah Datar regency in West Sumatra on December 1, 2018. (Photo by Adek Berry/AFP Photo)

A model stumbles as she presents a creation by Swiss designer Albert Kriemler as part of his Spring/Summer 2020 women's ready-to-wear collection show for fashion house Akris during the Paris Fashion Week in Paris, France, September 29, 2019. (Photo by Gonzalo Fuentes/Reuters)

(L-R) Pieter Van Lankveld, Jay Schippers, Ynze Oegema, Justin Kimmann, Teun Kivit and Twan Van Gendt compete during the Dutch National BMX Championships at Olympic Training Centre Papendal on October 11, 2020 in Arnhem, Netherlands. (Photo by Dean Mouhtaropoulos/Getty Images)

Men wear masks as they sit in the metro in Prague, Czech Republic, 17 March 2020. According to media reports, the Czech government decided to impose a two-week quarantine in the country on the evening of 15 March, and ban all international travel from 16 March 2020. Currently 383 cases of the coronavirus SARS-CoV-2, which causes the Covid-19 disease, have been officially confirmed in Czech Republic. (Photo by Martin Divisek/EPA/EFE)