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)

A Sikh warrior, wearing a huge turban attends the annual fair of “Hola Mohalla” in Anandpur Sahib, in the northern Indian state of Punjab, Monday, March 17, 2014. Believers from various parts of northern India collect at the religious fair to celebrate the festival of Holi in a tradition set by the tenth Sikh guru Guru Gobind Singh in the seventeenth century. Nihangs, or Sikh warriors, display their martial skills and attire during the fair, believed to be maintained in the exact tradition as set by the Guru. (Photo by Altaf Qadri/AP Photo)

“Himalayan Dog”. This dog just appeared out of nowhere and followed us for an entire week during our trekking trip in the Himalayan outback. He always used to sleep in front of our tent and guarded us in the nights. When I decided to get up at 4 a.m. to climb the next 5000 m peak for sunrise he accompanied me as well. On the top he was sitting for the entire 30 minutes on this place looking straight into the countryside. Photo location: Ladakh, India. (Photo and caption by Sebastian Wahlhuetter/National Geographic Photo Contest)

Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)

Mother and daughter volunteers Niki, right, and Rachel practice their pancake tossing technique in the streets of Wimborne model town and gardens before taking part in the Wimborne Minster virtual pancake race, in Wimborne, England, Tuesday February 16, 2021. Although a physical race cannot take place this year due to the coronavirus restrictions, Wimborne Minster has invited people to film themselves tossing a pancake for 30 seconds and posting it to Facebook. (Photo by Andrew Matthews/PA Wire via AP Photo)

Flames from the County fire burn above Cache Creek Casino Resort on Saturday, June 30, 2018, in Capay, Calif. (Photo by Noah Berger/AP Photo)

Newlyweds pose on a zebra crossing for wedding photographers during the 2018 soccer World Cup in Samara, Russia, Sunday, July 8, 2018. (Photo by Frank Augstein/AP Photo)

A police officer escorts a civilian away from the scene of a shooting, Sunday, July 22, 2018, in Toronto, Canada. A gunman opened fire in central Toronto on Sunday night, injuring 13 people including a child. Two dead including gunman, police reported. (Photo by Frank Gunn/The Canadian Press via AP Photo)