A handout photograph provided by Brian Kubicki of Costa Rican Amphibian Research Center on 26 April 2016 shows a “Crystal frog”, Hyalinobatrachium dianae (H. diane). This frog was discovered by US biologist Brian Kubicki and Costa Ricans Stanley Salazar and Robert Puschendorf in a rainy forest of Costa Rican caribbean after 40 years without notice of any new example of this kind. (Photo by Brian Kubicki/EPA/Costa Rican Amphibian Research Center)

Two Bulgarian tourists pose in front of the Eiffel Tower in Paris on their last day in the capital on March 24, 2014. (Photo by Franck Fife/AFP Photo)

Performers dressed as Ded Moroz, the equivalent of Santa Claus, and his granddaughter Snegurochka (Snow Maiden) take on shoe covers as they visit the Republican Scientific and Practical Centre of Pediatric Surgery in Minsk, Belarus, December 28, 2016. (Photo by Vasily Fedosenko/Reuters)

Children of the Roma community play as they cool off in a fountain in the main square of Pristina, Kosovo on June 14, 2017. (Photo by Armend Nimani/AFP Photo)

Two visitors take pictures of autumn leaves at Rikugien Garden Tuesday, December 10, 2019, in the Bunkyo district of Tokyo. (Photo by Jae C. Hong/AP Photo)

A plume of ash erupts from the Taal volcano in the Philippines on January 13, 2020. Situated on an island in the middle of a lake, it is one of the world's smallest volcanoes and has recorded at least 34 eruptions in the past 450 years. (Photo by Kenji Cheow/Magnus News)

A vendor decorates a sacrificial camel ahead of the Eid al-Adha festival, in Karachi, Pakistan, 23 August 2016. Eid al-Adha is the holiest of the two Muslims holidays celebrated each year, with this year will be celebrated on 02nd September. Eid al-Adha marks the yearly Muslim pilgrimage (Hajj) to visit Mecca, the holiest place in Islam. Muslims slaughter a sacrificial animal and split the meat into three parts, one for the family, one for friends and relatives, and one for the poor and needy. (Photo by Rehan Khan/EPA)

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