Shanghai Ballet dancers wearing masks practise in a dance studio in Shanghai, China, as the country is hit by an outbreak of the novel coronavirus, February 20, 2020. (Photo by Aly Song/Reuters)

Protesters wear gas masks in the front of the Romanian Environment Ministry in Bucharest March 4, 2019, to demand better air. Dozens of people holding placards reading “Our children don't breath air anymore” gather in the front of the Environment Ministry to ask for better breathable air in Bucharest. (Photo by Daniel Mihailescu/AFP Photo)

A man carrying vegetables is stopped by police at a barricade on a road during a 21-day nationwide lockdown to limit the spreading of coronavirus disease (COVID-19) in Chennai, India, March 25, 2020. (Photo by P. Ravikumar/Reuters)

A policeman wearing a coronavirus-themed outfit composed of helmet, mace and shield, gestures towards a vendor (L) at a market to raise awareness about social distancing, during a government-imposed nationwide lockdown as a preventive measure against the COVID-19 coronavirus in Chennai, on April 2, 2020. (Photo by Arun Sankar/AFP Photo)

A boy plays with a toy plane on the eve of a solar eclipse, in La Higuera, Coquimbo Region, in the Atacama desert about 580 km north of Santiago, on July 1, 2019. A total solar eclipse will be visible from small parts of Chile and Argentina on July 2. (Photo by Martin Bernetti/AFP Photo)

A woman wears a mask with printed lips, amid the spread of the new coronavirus in Caracas, Venezuela, Thursday, April 30, 2020. (Photo by Ariana Cubillos/AP Photo)

The face of a graduating student is displayed on a tablet attached to a robot during a “cyber graduation” ceremony at a school on May 22, 2020 in Taguig, Metro Manila, Philippines. Robots represented some 179 graduating students of the Senator Rene Cayetano Science and Technology High School during a graduation ceremony that was streamed online, as mass gatherings remain prohibited in the country under the Philippine government's lockdown to curb the spread of the coronavirus. The robots were developed by alumni of the school's robotics club, which used tablets to display the faces of the graduating students as they “marched” on stage to receive their diplomas. The Philippines' Department of Health has so far reported 13,434 cases of the coronavirus in the country, with at least 846 recorded fatalities. (Photo by Ezra Acayan/Getty Images)

Agriculture Secretary Sonny Perdue adjusts his mask before an event in the Roosevelt Room of the White House, Tuesday, May 19, 2020, in Washington. (Photo by Evan Vucci/AP Photo)