Young man making the O.K. sign. (Photo by George Marks/Retrofile/Getty Images). Circa 1950s

In this aerial photo taken on March 28, 2019 a hot air balloon flies over Putrajaya during the international hot air balloon festival in Putrajaya, Malaysia. (Photo by Mohd Rasfan/AFP Photo)

Models promote a condom brand at the first Shenzhen s*x Culture Festival on September 21, 2007 in Shenzhen of Guangdong Province, China. The festival aims to increase awareness about reproductive health and popularise s*x education. (Photo by China Photos/Getty Images)

A supporter of the Houthis has a poster attached to his waist of Iranian Major-General Qassem Soleimani, head of the elite Quds Force, who was killed in an air strike at Baghdad airport, during a rally to denounce the U.S. killing, in Saada, Yemen January 6, 2020. The writing on the poster reads: “God is the Greatest, Death to America, Death to Israel, Curse on the Jews, Victory to Islam”. (Photo by Naif Rahma/Reuters)

A fighter of Libyan forces allied with the U.N.-backed government fires a shell with Soviet made T-55 tank at Islamic State fighters in Sirte, Libya, August 2, 2016. (Photo by Goran Tomasevic/Reuters)

Mask dancers take part in a parade during the the International Festival of Masquerade Games “Surva” in the town of Pernik, some 30 km from Sofia, Bulgaria, January 31, 2016. (Photo by Vassil Donev/EPA)

This summer China opened its door to its first private bodyguard training company in Beijing. Genghis Security Academy offers rigorous training course which includes aquatic training, martial arts, vehicle safety training and other necessary skills. Photo: Female and male trainees run during a bodyguard training program at the boot camp of Genghis Security Academy in Beijing, China. (Photo by ImagineChina/The Grosby Group)