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)

Performers of Everland Amusement Park present the part of Christmas Fantasy in downtown of Myundong in Seoul, South Korea on December 3, 2019. (Photo by Seokyong Lee/Penta Press/Rex Features/Shutterstock)

Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)

This handout picture taken and released by Thai Royal Household Bureau on December 12, 2019 shows Thailand's Princess Bajrakitiyabha (L) and Princess Sirivannavari sit in their barge during the Royal Barge procession in Bangkok. The Royal barge procession is the final event of the coronation of Thailand’s King Maha Vajiralongkorn. (Photo by Thai Royal Household Bureau via AFP Photo/Handout)

Female activists perform a choreography originated in Chile, and inspired by the Chilean feminist group Las Tesis, to protest against gender violence and patriarchy in front of the Greek parliament at Athens' Syntagma Square on December 22, 2019. (Photo by Louisa Gouliamaki/AFP Photo)

Swimmers take part in the annual Christmas Day swim in Porthcawl, Wales, England on December 25, 2019. (Photo by Ben Birchall/PA Images via Getty Images)

Syrian fighters from the Turkish-backed National Liberation Front (NLF) fire a missile against regime positions on May 13, 2019 in the rebel-held northern part of Syria's Hama province. Clashes on the edge of a jihadist bastion in northwestern Syria have killed at least 42 fighters in 24 hours, a monitor said today, after regime bombardment on the region devastated health services. (Photo by Omar Haj Kadour/AFP Photo)

Triplet sisters Natalia, Irina and Tatiana Mironenko attend a rehearsal while preparing for examination performances staged by the graduates of the folk dance faculty of the Krasnoyarsk choreographic college in Krasnoyarsk, Russia May 13, 2019. All three 19-year-old sisters are expected to join the renowned Krasnoyarsk state academic dance ensemble of Siberia after the graduation. (Photo by Ilya Naymushin/Reuters)