Blue, white and red brassieres, the colours of the French national flag, hang from a balcony in Marseille, France, November 27, 2015 as the French President called on all French citizens to hang the tricolour national flag from their windows on Friday to pay tribute to the victims of the Paris attacks during a national day of homage. (Photo by Jean-Paul Pelissier/Reuters)

A women wearing a mask to protect from extreme smog visits the Tiananmen Gate in Beijing December 8, 2015 as China's capital issues its first ever "red alert" for pollution. (Photo by Damir Sagolj/Reuters)

Sete Tamang, 20, avalanche survivor, waits to receive the bodies of his colleagues outside a morgue at Teaching Hospital in Katmandu, Nepal, Monday, October 20, 2014. Nepal was wrapping up rescue operations in its northern mountains Monday, saying all the hikers believed to have been stranded on a trekking route by a series of deadly blizzards are now safe. (Photo by Niranjan Shrestha/AP Photo)

A man wearing a mask looks on as he sells matresses in Manila, Philippines, January 8, 2020. (Photo by Willy Kurniawan/Reuters)

A model (R) wearing a dress adorned with chocolate stands backstage prior to a fashion show during the annual “Salon du Chocolat” expo in Seoul, South Korea on January 10, 2020. (Photo by Ed Jones/AFP Photo)

A model presents a creation by Obectra during Berlin Fashion Week in Berlin, Germany, January 15, 2020. The Berlin Fashion Week runs from​ 13 to 17 January. (Photo by Annegret Hilse/Reuters)

A surfer takes some air off a wave while surfing after sunset in Cardiff, California, U.S., January 7, 2020. (Photo by Mike Blake/Reuters)

Kashmiri woman takes part in a physical test of a recruitment rally for the Special Police Officers (SPO) in Jammu and Kashmir Police, in Srinagar on December 6, 2019. As many as 23,000 people have applied for posts in the Special Police Officers (SPO) in Jammu and Kashmir Police and 100 positions will filled in the current phase of recruitment, local authorities said. (Photo by Tauseef Mustafa/AFP Photo)