South Korean singer CL performs during the closing ceremony of the 2018 Winter Olympics in Pyeongchang, South Korea, Sunday, February 25, 2018, after 17 days of hard- fought competition. Olympic fire went out. (Photo by Natacha Pisarenko/AP Photo)

in Qayyarah, about 31 miles (50 km) south of Mosul, Iraq, Sunday, October 23, 2016.in Qayyarah, some 50 kilometers south of Mosul, Iraq, Sunday, Oct. 23, 2016. Islamic State fighters torched a sulfur plant south of Mosul, sending a cloud of toxic fumes into the air that mingled with oil wells the militants had lit on fire to create a smoke screen. (Photo by Marko Drobnjakovic/AP Photo)

Two dummy tanks being pushed along a road by German soldiers. (Photo by Hulton Archive/Getty Images). Circa 1925

A North Korean soldier throws a stone towards a photographer on the banks of the Yalu River in the North Korean town of Sinuiju, opposite the Chinese border city of Dandong October 21, 2006 in Sinuiju, Democratic People's Republic of Korea. (Photo by Cancan Chu/Getty Images)

Catherine, Duchess of Cambridge speaks to soldiers as she arrives at Calgary Airport on July 7, 2011 in Calgary, Canada. (Photo by Chris Jackson/Getty Images)

Soldiers evacuate a hostage from a mass shooting scene at the Terminal 21 shopping mall in Nakhon Ratchasima, Thailand, 09 February 2020. According to media reports, at least 21 people were killed, and as many as 30 wounded after a Thai soldier, identified as 32-year-old Jakraphanth Thomma, went on a shooting rampage with a M60 machine gun in the city of Nakhon Ratchasima, also known as Korat. Thomma held an unknown number of people hostage within the Terminal 21 shopping mall for around 17 hours before being shot and killed in a police operation. (Photo by Rungroj Yongrit/EPA/EFE)

In this Wednesday, August 20, 2014 photo released by Red Bull, Maikel Melero of Spain warms up prior to the fifth stage of the Red Bull X-Fighters World Tour in the South African savanna of Pretoria, South Africa. (Photo by Joerg Mitter/AP Photo/Red Bull)