“Be prepared” is the motto of petite Doris Sherrell, vocalist and dancer with “Blackouts of 1942”. In the event of a bombing, the young lady had her social security number tattooed on one leg by artist Jack Julian, and address placed on the other limb for means of identification in Los Angeles, September 29, 1942. (Photo by AP Photo)

An Army Sikorsky R-5 helicopter, undergoing record trials, demonstrates its lifting power by carrying 17 persons and pilot aloft as female onlookers wave in Bridgeport, Conn., January 10, 1946. During the tests records were claimed for altitude speed and both altitude and speed with payload. (Photo by Anthony Camerano/AP Photo)

British housewives toss pancakes in skillets as they run through the streets of Olney, England, in the community's annual race which follows a 500-year-old tradition, February 6, 1951. Mrs. Isabel Dix, 22, extreme right, won the race covering the 415 yards from the Parish pump to the door of Sts. Peter and Paul church in one minute, 12.1 seconds. (Photo by AP Photo)

Technical staff take shelter as a helicopter takes off prior to the Nendaz Freeride skiing and snowboard competition, a Freeride World Tour Qualifier (FWQ) event, on the Mont Gond in Nendaz, Switzerland on March 21, 2018. (Photo by Valentin Flauraud/EPA/EFE/Rex Features/Shutterstock)

Revellers chat on Havana's Malecon seafront before performing at a carnival parade, Cuba, August 12, 2016. (Photo by Alexandre Meneghini/Reuters)

President Calvin Coolidge rides in a car during his inaugural parade in Washington, D.C., U.S. in March 1925. (Photo by Reuters/Library of Congress)

People smear black ash with hands onto each other to wish for good luck and fortune during a traditional festival of the Yi ethnic minority in Qiubei County, Yunnan province, China July 18, 2017. (Photo by Ren Dong/Reuters/CNS)

Portraits single nominee: Dakar fashion, by Finbarr O’Reilly. Curious residents and a street vendor selling material look on as models Diarra Ndiaye, Ndeye Fatou Mbaye and Malezi Sakho wear outfits by the Senegalese designer Adama Paris in the Medina neighbourhood of Senegal’s capital, Dakar. (Photo by Finbarr O’Reilly/World Press Photo 2019)