Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)

Afghan children wait as their mothers receive treatment at a USAID-funded health center on September 7, 2011 in Farza, Afghanistan. Almost 10 years after the 9/11 attacks and the U.S. invasion of Afghanistan, the U.S. government funds some of 500 Afghan health facilities nationwide, most run by non-governmental organizations contracted by the Afghan Ministry of Public Health. (Photo by John Moore/Getty Images)

Colonel Roscoe Turner, the pilot of an American Boeing plane, showing his wife a model of the plane, at the airfield in Mildenhall. (Photo by R. Wesley/Fox Photos/Getty Images). 19th October 1934

U.S. Army soldiers carry an injured soldier who was shot in the leg, through a poppy field on April 24, 2011 in the Arghandab River Valley, Kandahar Province, Afghanistan. The injured was evacuated to a waiting Blackhawk UH-60A helicopter by Task Force Thunder Brigade, Charlie company 1st of the 52nd Aviation regiment from Fairbanks, Alaska. It is feared that as weather improves with the approaching summer that the casualty toll will rise. (Photo by Paula Bronstein/Getty Images)

Homeless people receive free food offered by the Telangana state governement during a 21-day government-imposed nationwide lockdown as a preventive measure against the COVID-19 coronavirus in Hyderabad on March 26, 2020. (Photo by Noah Seelam/AFP Photo)

Medical workers walk by a police robot at the Wuhan Tianhe International Airport after travel restrictions to leave Wuhan, the capital of Hubei province and China's epicentre of the novel coronavirus disease (COVID-19) outbreak, were lifted, April 8, 2020. (Photo by Aly Song/Reuters)

In this Wednesday, April 15, 2020 file photo, a motorcycle delivery man rides past a billboard urging people to stay home over the coronavirus pandemic in Dubai, United Arab Emirates. Wealthier Western countries are considering how to ease lockdown restrictions and start taking gradual steps toward reviving business and daily life. But many developing countries, particularly in the Middle East and Africa, can hardly afford the luxury of any misstep. (Photo by Jon Gambrell/AP Photo/File)

A serviceman of Russia's Emergencies Ministry wearing protective gear disinfects Moscow's Leningradsky railway station on May 19, 2020, amid the COVID-19 coronavirus pandemic. (Photo by Kirill Kudryavtsev/AFP Photo)