Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

Palestinian female Hamas security officers demonstrate their skills during a graduation ceremony in the northern Gaza Strip, Wednesday, April 2, 2014. 1200 officers graduated from advanced training courses that lasted one year in Gaza police academy of Hamas. (Photo by Adel Hana/AP Photo)

A costumed fan attends Comic-Con International 2014 – Day 1 on July 24, 2014 in San Diego, Calif. (Photo by Joe Scarnici/FilmMagic/Getty Images)

A South Sudanese People Liberation Army (SPLA) soldier patrols the streets in Malakal on January 21, 2014. (Photo by Harrison Ngethi/AFP Photo)

A female goalkeeper saves the ball at the Mathare Environmental Conservation Youth Center during a soccer match to celebrate the International Women's day in Nairobi, Kenya, March 8, 2017. (Photo by Thomas Mukoya/Reuters)

Demi Rose attends Sixty6 Magazine – issue two launch party at Paper club on March 22, 2017 in London, England. (Photo by Splash News and Pictures)

The Baby Nager dragon, from DreamWorks’ new “How to Train Your Dragon” Live Spectacular touring musical, shows off it’s colors outside of the New York Public Library. (Photo by Mark Von Holden)

Yuanlei Liao, the singer of hardcore band called Thank Ray wears a read scarf after performing on the stage of Mao Live House during the club's last public concert night in central Beijing, China April 23, 2016. Mao Live House, a prominent live rock music venue in Beijing, shut its doors on the weekend, the latest closure to hit China's rock music scene. Owner Li Chi said the club, popular among fans of punk, metal and alternative rock since it opened nine years ago, was forced to close due to tighter rules on live performances. (Photo by Damir Sagolj/Reuters)