Participants arrive at the finish line during the annual Maldon Mud Race in Maldon, east England on May 7, 2017. Originating in 1973, the race involves competitors racing around a course through the River Blackwater in Essex at low tide. (Photo by Daniel Leal-Olivas/AFP Photo)

Runners gather at the start line for the annual “Santa Speedo Run”, a charity race through the streets of the Back Bay neighborhood of Boston. (Photo by Gretchen Ertl/Reuters)

Chinese special policemen rank in a line of battle during an anti-terror drill at a training base of Chengdu Armed Police Headquarters on September 28, 2005 in Chengdu of Sichuan Province, China. (Photo by China Photos/Getty Images)

Girls cry as they get separated from their family at the border line dividing Macedonia and Greece August 21, 2015. At least 1,000 migrants and refugees pressed against Macedonian police lines on the Greek-Macedonian border on Friday and at least 10 people appeared to faint in the crush. People could be heard screaming and medical workers raced to treat those who passed out or were hurt. The crush ensued after police let several hundred through into Macedonia, having kept them out since Thursday under an emergency decree. (Photo by Ognen Teofilovski/Reuters)

In this Tuesday, June 4, 2019, photo, a Yamanote Line train travels above commuters walking across the crossing during evening rush hours in the Shinjuku district of Tokyo. Operated by the East Japan Railway Co., the Yamanote Line in Tokyo makes a loop around the center of the city, connecting 29 stations that include key stops such as Shinjuku, Shibuya and Ikebukuro. A complete loop of about an hour offers scenes of Japanese daily lives. (Photo by Jae C. Hong/AP Photo)

Soldiers stand in line outside portable toilets during a military parade to celebrate the 206th anniversary of Colombia's independence in Bogota, Colombia, July 20, 2016. (Photo by John Vizcaino/Reuters)

Dogs pose for a photo in the likeness of a photo time line of Face Book during the “Blocao” dog carnival parade in Rio de Janeiro, Brazil, Saturday, February 14, 2015. (Photo by Silvia Izquierdo/AP Photo)

A service member of the Ukrainian armed forces is seen at fighting positions on the line of separation from pro-Russian rebels in Donetsk region, Ukraine on April 10, 2021. (Photo by Oleksandr Klymenko/Reuters)