A guard wears a protective mask as he stands at the entrance to the Forbidden City as it re-opened to limited visitors or the May holiday, on May 1, 2020 in Beijing. Photo by Kevin Frayer/Getty Images.

A guard wears a protective mask as he stands at the entrance to the Forbidden City as it re-opened to limited visitors or the May holiday, on May 1, 2020 in Beijing. Photo by Kevin Frayer/Getty Images.

A guard wears a protective mask as he stands at the entrance to the Forbidden City as it re-opened to limited visitors or the May holiday, on May 1, 2020 in Beijing. Photo by Kevin Frayer/Getty Images.