Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

An Indian street vendor selling bananas naps on his fruit cart at the roadside in New Delhi on June 3, 2015. (Photo by Money Sharma/AFP Photo)

A production department of a textile factory is seen abandoned in Kaduna, Nigeria November 3, 2016. President Muhammadu Buhari hopes to revive the once flourishing textile and leather industries in northern Nigeria to end the country's dependence on oil exports and diversify Africa's biggest economy. (Photo by Afolabi Sotunde/Reuters)

Members of the Women's Fire Brigade with their Chief Officer, March 1916. (Photo by Topical Press Agency)

A dragster supercharger hits cameraman Joe Rooks of Bowling Green, Ohio, in the back at the U.S. Nationals N.H.R.A. drag races in Indianapolis, Indiana, on Saturday, September 1, 1979. Rooks was knocked flat by the heavy blower from a dragster that turned over and disintegrated near Rooks. Rooks died en route to the hospital. (Photo by Chuck Robinson/AP Photo)

Two styles of cleaned bird's nest, Yan Zhan (L) and Su Zhan (R) await repacking at a processing plant in Kuala Lumpur, February 17, 2015. Prized in China for is alleged health benefits for hundreds of years, nests made from swiftlets' saliva are being mixed into coffee and cereal as the Southeast Asian producers of the delicacy seek to broaden its appeal, and their profit margins. The nests are among the world's most expensive foods, selling for up to $2,500 a kg and the swiftlets that weave them are indigenous to Indonesia, Malaysia, Thailand and Vietnam. (Photo by Olivia Harris/Reuters)

People spend the summer at Qingdao seaside in Shandong, China on July 3, 2019. The maximum temperature of Qingdao beach was 26 degrees Celsius on that day, and all the 9 sea bathing places were open, attracting a large number of visitors to the seaside to enjoy the cool world. (Photo by Huang Jiexian/ZUMA Press)

“I have seen batches of banknotes worth more than $2.6 million, but beyond all doubt, gold bars look much more attractive!”. – Shamil Zhumatov. Photo: Cooling-down gold ingot. March 14, 2013; Tien Shan mountains, Kyrgyzstan. (Photo by Shamil Zhumatov/Reuters)