A girl goes to school just before sunrise in Frankfurt, Germany, Wednesday, December 11, 2019. (Photo by Michael Probst/AP Photo)

Anti-frost candles burn in apricot plantations to protect flowering buds and blossoms from frost in the midst of the Swiss Alps, in Saxon, Canton of Valais, Switzerland, 05 April 2019. With an unusually low temperature forecast for the season, fruit growers try to protect their buds from frost damage with two different means, icy water or large candles. (Photo by Valentin Flauraud/EPA/EFE)

Young Ukrainians dance at nightclub House of Meteorologists, May 23, 2014. Sunday's upcoming election in Ukraine has not only exposed the divide between east and west, but between old and young. Unlike their elders, younger people have no memory of Soviet life, and most see themselves as Ukrainian. (Photo by Evelyn Hockstein/The Washington Post)

Widows, who have been abandoned by their families, light sparklers after offering prayers on the banks of the river Yamuna as part of Diwali celebrations organised by non-governmental organisation Sulabh International in Vrindavan, Uttar Pradesh October 21, 2014. (Photo by Ahmad Masood/Reuters)

Riot police scuffle with pro-democracy students after hundreds of protesters stormed into a restricted area at the government headquarters, after a rally ahead of the October 1 “Occupy Central” civil disobedience movement in Hong Kong September 27, 2014. Hong Kong riot police used pepper spray on Saturday to disperse dozens of students who had stormed government headquarters, but an equal number held their ground in protests against Beijing's tightening grip on the city. (Photo by Tyrone Siu/Reuters)

A zoo staff feeds crocodiles as visitors look on at the Malabon Zoo in Malabon City, north of Manila, Philippines 21 December 2017. Wearing Santa Claus hats for the upcoming Christmas season, owner Manny Tangco (R, holding megaphone) and some select animals gave visitors a tour of the 28-year-old zoo. (Photo by Rolex Dela Pena/EPA/EFE)

Revellers take part in the “Canto a la Tierra” parade on January 3, 2018, during the Carnival of Blacks and Whites in Pasto, Colombia, the largest festivity in the south- western region of the country. More than 10,000 people among artists, craftsmen and revellers take part in the Blacks and Whites Carnival, which has its origins in the mix of the multiple Andean, Amazonian and Pacific cultural expressions. It is celebrated every year from January 2 to 6 in the city of Pasto and is part of UNESCO's Intangible Cultural Heritage of Humanity since 2009. (Photo by Luis Robayo/AFP Photo)

Indian students smear coloured powder during an event to celebrate the Hindu festival of Holi in Kolkata on February 26, 2018. Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 1 this year. (Photo by Dibyangshu Sarkar/AFP Photo)