Swan Uppers try to capture a swan and it's Cygnets on the River Thames near Windsor, England, during Swan Upping, with Windsor Castle in background, Tuesday July 20, 2021. The ancient tradition of Swan Upping is the annual census to gauge the numbers and health of the swan population on the River Thames. (Photo by Steve Parsons/PA Wire via AP Photo)

A US soldier (C) point his gun towards an Afghan passenger at the Kabul airport in Kabul on August 16, 2021, after a stunningly swift end to Afghanistan's 20-year war, as thousands of people mobbed the city's airport trying to flee the group's feared hardline brand of Islamist rule. (Photo by Wakil Kohsar/AFP Photo)

Switzerland's cyclist Marlen Reusser reacts after placing second in the women' elite time trial race of the UCI World Championships Road Cycling Flanders 2021, in Bruges, on September 20, 2021. UCI World Championships Road Cycling Flanders 2021 takes place from September 19 until September 26, 2021, in several cities in the Belgian region of Flanders. (Photo by Simon Wilkinson/BELGA via AFP Photo)

A woman lays dead outside the Redemption Hospital on Saturday September 20, 2014 in Monrovia, Liberia. Ebola patients come to the hospital, which has become a transfer and holding center to intake Ebola patients, but there is no space and some die while waiting outside. Redemption is located in one of the poorest neighborhoods of Monrovia that locals call "New Kru Town”. Health workers are overwhelmed with a constant stream of new patients since the Ebola outbreak. (Photo by Michel du Cille/The Washington Post)

Students from St Andrew's University indulge in a tradition of covering themselves with foam to honour the “academic family” on October 20, 2014, in St Andrews, Scotland. Every November the “raisin weekend” which is held in the university's Lower College Lawn, is celebrated and a gift of raisins (now foam) is traditionally given by first year students to their elders as a thank you for their guidance and in exchange they receive a receipt in Latin. (Photo by Jeff J. Mitchell/Getty Images)

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 Ivanpah Solar Electric Generating System is seen in an aerial view on February 20, 2014 in the Mojave Desert in California near Primm, Nevada. The largest solar thermal power-tower system in the world, owned by NRG Energy, Google and BrightSource Energy, opened last week in the Ivanpah Dry Lake and uses 347,000 computer-controlled mirrors to focus sunlight onto boilers on top of three 459-foot towers, where water is heated to produce steam to power turbines providing power to more than 140,000 California homes. (Photo by Ethan Miller/Getty Images)

Katjinga, a Rhodesian ridgeback dog who lives on a 20-acre farm in Germany, adopted an abandoned pot-bellied piglet in August 2009. The tiny black piglet, named Paulinchen, had been so small at birth that her mother likely overlooked it. Katjinga's owner, Roland Adam, found the piglet alone and cold and brought it to his 8-year-old dog. (Photo by Fame Pictures)