A female member of Romania's military adjusts her hat before taking part in the national day military parade in Bucharest, Romania, Friday, December 1, 2017. Thousands of Romanian troops staged a military parade to celebrate Romania's national day, but key politicians didn't attend, signaling tensions between the president and the ruling left-wing coalition over plans to revamp the justice system. (Photo by Vadim Ghirda/AP Photo)

Police, bystanders and soldiers aid a fallen soldier at the War Memorial as police respond to an apparent terrorist attack on October 22, 2014 in Ottawa, Canada. A gunman is believed to have shot a soldier as he was standing guard at the National War Memorial in Ottawa. It is believed police then chased the man into the main parliament building at Parliament Hill, where more shots were fired. (Photo by Wayne Cuddington/Postmedia/Barcroft Media/ABACAPress)

Attendee Emily poses for a picture at 2017 Comic-Con International on July 20, 2017 in San Diego, California. (Photo by Mike Blake/Reuters)

The snaps show photographers from around the world, who are willing to do just about anything for the perfect picture – whether that be tussling with a seal or withstanding a sharp shove from an angry gorilla. Other brave snappers can be seen getting up close and personal with leopards and great white sharks as they persist in getting the ultimate wildlife shot. Here: Christophe Vasselin gets pushed over by a gorilla. (Photo by Christophe Vasselin/Caters News Agency)

A security guard walks past a giant Doctor Who poster at the “Doctor Who 50th Celebration” event in the ExCeL centre on November 22, 2013 in London, England. The sold-out three day event in the ExCeL London convention centre celebrates 50 years of the show which has seen 11 actors play the role of Doctor Who and receives a worldwide cult following. (Photo by Oli Scarff/Getty Images)

A supporter of China's President Xi Jinping waits on the Mall for him to pass during his ceremonial welcome, in London, Britain, October 20, 2015. Xi is on a State visit to Britain. (Photo by Peter Nicholls/Reuters)

“Red Arrows” at the 2016 royal air tattoo, RAF Fairford, UK. By Jonny Williams, finalist: action. (Photo by Jonny Williams/UK National Geographic Traveller Photography Competition 2018)

A group of costumed fans attend Comic-Con International at San Diego Convention Center on July 12, 2015 in San Diego, California. (Photo by Daniel Knighton/Getty Images)