Flames from a burning barricade lit by pro-democracy protesters is reflected in the windows of a passing bus as passengers watch on during a protest gathering in front of Mong Kok police station on September 22, 2019 in Hong Kong, China. Pro-democracy protesters have continued demonstrations across Hong Kong, calling for the city's Chief Executive Carrie Lam to immediately meet the rest of their demands, including an independent inquiry into police brutality, the retraction of the word “riot” to describe the rallies, and genuine universal suffrage, as the territory faces a leadership crisis. (Photo by Chris McGrath/Getty Images)

Hundreds of students take part in the traditional Raisin Monday foam fight on St Salvator’s Lower College Lawn in Scotland on October 21, 2019. The messy display is the culmination of a weekend of festivities where first years say thank you to their more senior student “parents” for mentoring them. (Photo by Jane Barlow/PA Images via Getty Images)

This photo taken on November 4, 2019 shows people taking part in a fish catching competition in a paddy field in Leishan county in China's southwestern Guizhou province, to celebrate the new year festival Miao people. (Photo by AFP Photo/China Stringer Network)

Iranian soccer fan wait for the start of the group B match between Iran and Spain at the 2018 soccer World Cup in the Kazan Arena in Kazan, Russia, Wednesday, June 20, 2018. (Photo by Diego Azubel/EPA/EFE)

The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)

Some people prepare to catch offerings thrown by Tengger tribe people into the crater of Bromo volcano to in Probolinggo, East Java province, on June 30, 2018, as part of Yadnya Kasada festival which falls on the 14th day of the Kasada month based on the traditional Hindu lunar calendar. (Photo by Juni Kriswanto/AFP Photo)

A unidentified woman protests at Broad Street for the pending arrival of Vice President Mike Pence at the Union League, in Philadelphia, Monday, July 23, 2018. Dozens of demonstrators dressed as characters from the novel-turned-TV series “The Handmaid's Tale” descended on downtown Philadelphia to protest Pence’s visit. (Photo by Jose F. Moreno/The Philadelphia Inquirer via AP Photo)

The Mayon volcano continues to erupt as the sun sets behind Legazpi city, Thursday, January 25, 2018 in Albay province, roughly 340 kilometers, (200 miles) southeast of Manila, Philippines. (Photo by Bullit Marquez/AP Photo)