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)

The “Escape Velocity” moving sculpture by artist group Poetic Kinetics looms over Coachella festivalgoers on the Empire Polo Field, on the first day of the 2014 Coachella Music and Arts Festival in Indio, California, on April 11, 2014. (Photo by Chris Pizzello/Invision)

“Are you here for the Winery Tour?” This is a Western Grey Kangaroo caught lounging in the wineries of the Adelaide Hills in South Australia. This past Autumn has been a spectacular time for wildlife viewing and I got lucky to spot this guy while mountain biking in the hills. Such a funny stance it just begs the question... Have you been drinking? ...and or... Are you here for the Winery Tour? Such a spontaneous moment I figured it would be perfect for an entry. I hope you like it! Cheers. Photo location: Adelaide Hills, South Australia, Australia. (Photo and caption by Greg Snell/National Geographic Photo Contest)

Soccer player David Beckham (C) with Cruz Beckham (L) and Romeo Beckham (R) get slimed onstage during Nickelodeon Kids' Choice Sports Awards 2014 at UCLA's Pauley Pavilion on July 17, 2014 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

An Iraqi man cooks traditional Masgouf fish on a barbecue for sale in the Karada market July 02, 2014. Masgouf, one of the national dishes of Iraq is a grilled carp seasoned with olive oil, rock salt, tamarind and ground turmeric. (Photo by Scott Nelson for the Washington Post)

Myanmar's military parade to mark the 72nd Armed Forces Day in the capital Naypyitaw, Myanmar March 27, 2017. (Photo by Soe Zeya Tun/Reuters)

Singer Rita Ora enters her hotel on April 27, 2017 in New York City. (Photo by MEGA)

In this June 16, 2017 photo, Batel Delciner, 23, removes wood from a furnace to lower the heat cooking sugar juice at the Ti Jean distillery, which produces clairin, a sugar-based alcoholic drink, in Leogane, Haiti. The broth is cooked for about four hours after a fermentation period of four to eight days. (Photo by Dieu Nalio Chery/AP Photo)