Students hold their weapons before the swearing in ceremony for the military students, in Bucharest, Romania, Wednesday, October 25, 2017. The Romanian Army is proudly celebrating their Army Day and marking 100-years since the landmark battle of Marasesti, a key World War I battle in 1917 when Romanian and Russian soldiers defeated German troops, halting a German offensive. (Photo by Vadim Ghirda/AP Photo)

A Dancer, dressed with the traditional Yi costume, waits to perform at the Torch Festival, in Xichang, China's Sichuan province on July 27, 2016. As a result of fast urbanisation in the rural area of China Like Lienchang prefecture, the traditional costume is fading away for the Yi people in daily life. (Photo by Fred Dufour/AFP Photo)

An Afghan National Army (ANA) soldier assigned to the Mobile Strike Force Kandak fires a RPG-7 rocket-propelled grenade launcher during a live-fire exercise supervised by the Marines with the Mobile Strike Force Advisor Team on Camp Shorabak, Helmand province, Afghanistan, May 20, 2013. The Marines with the Mobile Strike Force Advisor Team instructed and mentored their ANA counterparts on how to properly utilize their weapons systems. (Photo by SSgt Ezekiel R. Kitandwe/RCT 7)

The northern lights, or aurora borealis, appear in the sky over the Bamburgh lighthouse at Stag Rock in Northumberland, England on September 28, 2016. (Photo by Owen Humphreys/PA Wire via ZUMA Press)

Sweden's Mikael Ymer slips and falls in the first round match of the French Open tennis tournament against Serbia's Novak Djokovic at the Roland Garros stadium in Paris, France, Tuesday, September 29, 2020. (Photo by Alessandra Tarantino/AP Photo)

Double amputee dog Cora Rose balances on her hind legs to watch Zach Skow repairing her cart on a street in Washington, U.S., May 15, 2019. Cora Rose serves in a prisoner therapy program founded by Skow called “Pawsitive Change” in California. (Photo by Kevin Lamarque/Reuters)

A Filipino teacher checks a picture of a student shown on a tablet that is attached to robot during a graduation ceremony at a school in Taguig City, Philippines, 22 May 2020. At least 179 high school students received their diploma during an online graduation ceremony that was beamed live on Facebook as a measure to prevent the spread of the coronavirus and COVID-19 disease. (Photo by Francis R. Malasig/EPA/EFE)

Palestinian men perform fire breathing on the beach as an entertainment for children during the summer vacation in Gaza City on August 1, 2019. (Photo by Mohammed Abed/AFP Photo)