Riot security forces clash with demonstrators as a motorcycle is set on fire during a protest against Venezuelan President Nicolas Maduro's government in San Cristobal, Venezuela May 29, 2017. (Photo by Carlos Eduardo Ramirez/Reuters)

Actors dressed up as zombies walk around while posing for photos with passers-by in New York's Times Square on Friday, October 10, 2014 as a promotion for the season premiere of AMC's “The Walking Dead” this Sunday, October 12, 2014. (Photo by Gordon Donovan)

Captain George Ash lies on his back as he prepares to shoot the bowl from the clay pipe held between a blindfolded corporal's teeth. (Photo by Fox Photos/Getty Images). 18th April 1932

Fans gather to watch a FIFA World Cup Russia 2018 football match between Brazil and Costa Rica on a giant screen at Alzirao neighborhood in Rio de Janeiro, Brazil on June 22, 2018. (Photo by Carl De Souza/AFP Photo)

Getting her tongue pierced was “exciting and scary” says a teen who succumbed to pressure from her best friend in Austin, Texas, February 22, 2008. This image is featured in National Geographic's exhibition “Women of Vision: National Geographic Photographers on Assignment”, on view at the Palm Beach Photographic Centre, Jan. 22 - Mar. 22, 2015. (Photo by Kitra Cahana/National Geographic)

Hot air balloons fly over the sky in Chiang Mai province, northern Thailand, December 6, 2014. The two-day International Balloon festival 2014 featuring balloon pilots from Germany, Spain, Netherlands, Britain, and Czech Republic is held on December 06-07 2014 to celebrate Thai King Bhumibol Adulyadej's 87th birthday and also aimed to promote the tourism industry in Chiang Mai northern city. (Photo by Pongmanat Tasiri/EPA)

An Afghan refugee girl shows her younger brother a calf in a slum on the outskirts of Islamabad, Pakistan, Friday, February 6, 2015. (Photo by Muhammed Muheisen/AP Photo)

Civilians are led by members of pro-Russian self-defence units as they run outside a military base during an assault in the Crimean town of Belbek near Sevastopol March 22, 2014. Russian troops forced their way into a Ukrainian airbase in Crimea with armored vehicles, automatic fire and stun grenades on Saturday, injuring a Ukrainian serviceman and detaining the base's commander for talks. (Photo by Vasily Fedosenko/Reuters)