Marines finish a 10 kilometer training hike carrying 55 pound (25 kg) packs during Marine Combat Training (MCT) on February 22, 2013 at Camp Lejeune, North Carolina. Since 1988 all non-infantry enlisted male Marines have been required to complete 29 days of basic combat skills training at MCT after graduating from boot camp. MCT has been required for all enlisted female Marines since 1997. About six percent of enlisted Marines are female. (Photo by Scott Olson/AFP Photo)

City buildings stand beyond the giant excavated hole left by the Mir mine, a former open pit diamond mine, in Mirny, Russia, on Tuesday, November 12, 2013. OAO Alrosa, the world's largest diamond producer, raised about $1.3 billion in an oversubscribed share sale from investors including Oppenheimer Funds Inc. and Lazard Ltd.'s asset-management unit, First Deputy Prime Minister Igor Shuvalov said. (Photo by Andrey Rudakov/Bloomberg)

A person drags a suitcase as a boy clings to it on a square in front of a railway station ahead of the Chinese Lunar New Year in Qingdao, Shandong province, January 28, 2014. About 3.62 billion trips will be made during the 40-day Spring Festival travel rush, which started from January 16, reported Xinhua News Agency citing a government official. (Photo by Reuters/China Daily)

A student wearing a face mask prays before the start of the annual college entrance examination amid the coronavirus pandemic at an exam hall in Seoul, South Korea, Thursday, December 3, 2020. South Korean officials are urging people to remain at home if possible and cancel gatherings as about half a million students prepare for a crucial national college exam. (Photo by Kim Hong-Ji/Pool Photo via AP Photo)

Alejandro Ccasa prays after waiting three days next to an empty oxygen tank for his uncle who has COVID-19 outside a refill shop where he is the first in line before it opens in Callao, Peru, early Tuesday, February 2, 2021. Ccasa said his family has one large tank and it gives about four hours of oxygen therapy. (Photo by Martin Mejia/AP Photo)

Female members of the PDI (Investigations Police of Chile) march during the traditional military parade as part of the independence day celebrations on September 19, 2021 in Santiago, Chile. This year the militar parade was celebrated with 30% of the staff present in pre-pandemic years. About 6,500 members of the Army, Navy, Air Force, Carabineros and PDI paraded. (Photo by Matias Basualdo/ZUMA Press Wire/Rex Features/Shutterstock)

Alina Serban (L) poses during a photo session for the poster of her show in Bucharest on October 20, 2021. Roma actress and playwright Alina Serban grew up watching TV and going to the theatre without any stories “with or about people like us” – something she set out to change, becoming the first to have her work on the stage of Bucharest's National Theatre. (Photo by Bogdan Dinca/AFP Photo)

An illuminated Christmas tree leans against the window of a damaged house in Mayschoss in the Ahrtal valley, southern Germany, Tuesday, December 14, 2021. The region was hit by floodings exactly five months ago, causing the death of about 180 people. Amid the mud and debris still clogging the streets from last summer's devastating floods, residents of the Ahr Valley in western Germany are trying to spark some festive cheer with Christmas trees. (Photo by Michael Probst/AP Photo)