A helicopter drops fire retardent to protect a property in Balmoral, 150 kilometres southwest of Sydney on December 19, 2019. A state of emergency was declared in Australia's most populated region on December 19, as a record heat wave fanned unprecedented bushfires. (Photo by Peter Parks/AFP Photo)

Fallen leaves cover the undergrowth as a commuter on a bicycle makes her way through the Tiergarten park in central Berlin on December 7, 2020. (Photo by Odd Andersen/AFP Photo)

A potential Banksy has appeared on Vale Street in Bristol, United Kingdom on December 10, 2020. The elusive artist is from the city and is known for creating new works without anyone catching him in the act. An image of an old woman sneezing without covering her mouth has been spotted on a wall in the Totterdown area – a possible nod to the current health crisis. Crowds are already gathering at the bottom of Vale Street – one of Britain's steepest roads – to take pictures and discuss. (Photo by South West News Service/Action Press)

A ballet dancer poses in a giant plastic bubble as she entertains Christmas shoppers in Melbourne on December 13, 2020. (Photo by William West/AFP Photo)

Masks based on real people's faces are diplayed at the Shuhei Okawara's mask shop in Tokyo, Japan on December 16, 2020. (Photo by Issei Kato/Reuters)

Santa Claus wears a mask as he pushes a sleigh full of curbside grocery orders to an Aldi customer at a parking lot in Palatine, Ill., Saturday, December 19, 2020. For this weekend only, Santa Claus is delivering groceries to Aldi customers in Palatine and several other towns in the Chicago area. (Photo by Nam Y. Huh/AP Photo)

University students demonstrate against the crisis in the public education, budget cuts and a tax reform project announced by the government of Ivan Duque in Medellin, Colombia on December 13, 2018. (Photo by Joaquín Sarmiento/AFP Photo)

Dozens of people participate in the religious pilgrimage to the National Shrine of El Rincon, in the municipality of Boyeros, in Havana, Cuba, 17 December 2018. As is customary every year, thousands of people in mass attend the shrine to pay tribute to Saint Lazarus, to whom the faithful come for personal requests and miracles. (Photo by Ernesto Mastrascusa/EPA/EFE)