A woman wearing a mask walks in the street of Nice, southern France, Sept. 6, 2020. (Photo by Serge Haouzi/Xinhua)

Masks are on sale at a bakery shop near Saint Martin Canal in Paris, France, May 29, 2020. (Xinhua/Gao Jing)

A woman wearing a mask walks in the street of Nice, southern France, Sept. 6, 2020. (Photo by Serge Haouzi/Xinhua)

A woman wearing a mask walks on the Champs Elysees Avenue in Paris, France, May 15, 2020. (Xinhua/Gao Jing)

A woman wearing a mask takes a selfie in the street of Nice, southern France, Sept. 4, 2020. (Photo by Serge Haouzi/Xinhua)

People wearing masks walk in the street of Nice, southern France, Sept. 4, 2020. (Photo by Serge Haouzi/Xinhua)

A woman wearing a mask walks in the street of Nice, southern France, Sept. 6, 2020. (Photo by Serge Haouzi/Xinhua)

A woman wearing a mask walks in the street of Nice, southern France, Sept. 4, 2020. (Photo by Serge Haouzi/Xinhua)

A woman wearing a mask walks in the street of Nice, southern France, Sept. 5, 2020. (Photo by Serge Haouzi/Xinhua)

A man wearing a mask walks in the street of Nice, southern France, May 15, 2020. (Photo by Serge Haouzi/Xinhua)

People wearing masks walk in the street of Nice, southern France, Sept. 4, 2020. (Photo by Serge Haouzi/Xinhua)

A statue wearing a mask is pictured in Nice, southern France, May 20, 2020. (Photo by Serge Haouzi/Xinhua)

A woman wearing a mask talks with her friend in Nice, southern France, Sept. 3, 2020. (Photo by Serge Haouzi/Xinhua)

A man wearing a mask visits the Eiffel Tower on its reopening day in Paris, France, June 25, 2020. (Xinhua/Gao Jing)