Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

Even upside down, a stereophonic turntable continues to play and hold the interest of Helen Sorowitz, a visitor to the New York High Fidelity Show in New York, September 9, 1960. (Photo by Ruben Goldberg/AP Photo)

A U.S. Army crew chief flying on board a CH-47F Chinook helicopter observes the successful test of flares during a training flight in Afghanistan, March 14, 2018. (Photo by Tech. Sgt. Gregory Brook/Reuters/U.S. Air Force)

A Muslim dervish sings a traditional Sufi song near a rally for the Mawlid al-Nabi holiday, marking the birthday of Islam's prophet, Muhammad, in Lahore, Pakistan, Sunday, November 10, 2019. To mark the holiday, thousands take part in religious processions, ceremonies and distribute free meals to the poor. (Photo by K.M. Chaudary/AP Photo)

Visitors look at an elephant swimming in a pool at Khao Kheow Zoo in Chonburi, east of Bangkok, Thailand on February 4, 2020. (Photo by Chaiwat Subprasom/SOPA Images/LightRocket via Getty Images)

A patient solves a rubik's cube at a temporary hospital converted from “Wuhan Livingroom” in central China's Hubei Province on February 10, 2020. In face of the outbreak of the novel coronavirus pneumonia epidemic, Wuhan authorities have transformed public venues such as exhibition centers and gymnasiums into temporary hospitals. The hospitals have a large capacity of treating patients with mild symptoms and play an important role in isolating the source of infection and cutting off the routes of infection during epidemic prevention. The first batch of patients was hospitalized on Feb. 5. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)

A dog wearing face mask is seen on a street as the country is hit by an outbreak of the novel coronavirus, in Shanghai, China on March 2, 2020. (Photo by Aly Song/Reuters)

Journalists practice social distancing outside a meeting to wrap up work on coronavirus economic aid legislation to prevent the spread of coronavirus disease (COVID-19) in Washington, U.S., March 21, 2020. (Photo by Mary F. Calvert/Reuters)