Students participate in an earthquake drill in their school in Santiago, November 13, 2014. Around one million people, which included students, teachers and parents, took part on Thursday in a drill that simulated a fictitious earthquake of a magnitude of 8.8 on the Richter scale, according to organizers. (Photo by Ivan Alvarado/Reuters)

Cambodian children sleep on a pavement at a park in Phnom Penh on July 8, 2016. (Photo by Tang Chhin Sothy/AFP Photo)

Children play football in Bujumbura, Burundi on March 19, 2015. (Photo by Carl de Souza/AFP Photo)

An employee of the National Park Service takes a selfie with President Barack Obama, left, in the background meeting with the crowd after a tour of Everglades National Park on Earth Day, Wednesday, April 22, 2015, in Florida. Obama used the visit to warn of the damage that climate change is already inflicting on the nation's environmental treasures. (Photo by Lynne Sladky/AP Photo)

Maja, a 40-year-old elephant, extends her trunk into a bakery as a customer buys a newspaper while Maja took a stroll through the neighborhood with her minders from a nearby circus on July 1, 2016 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

A woman in traditional Malaysian attire welcomes leaders to the official dinner at the venue of the Association of Southeast Asian Nations (ASEAN) Summit in Kuala Lumpur, Malaysia November 21, 2015. (Photo by Jorge Silva/Reuters)

11-year-old Balinese dancer girl Intan puts on makeup before she performs Mergapati Dance at a village event in Banjar Wangaye Kelod, Denpasar, Bali, Indonesia on November 19, 2017. To preserve traditional dances and culture, Balinese train their children to learn various traditional dances from childhood. (Photo by Mahendra Moonstar/Anadolu Agency/Getty Images)

Sugar gliders, Candy and Popcorn, enjoy their favourite food, Nectar, at Wild Life Sydney Zoo on February 14, 2017 in Sydney, Australia. The treat made up of honey, high protein baby cereal and egg yolks is the human equivalent to chocolate to the Sugar Gliders. St. Valentine's Day or the Feast of Saint Valentine began as a celebration of the early Christian Saint Valentinus. From the 18th Century onwards it has steadily transformed into a celebration of romantic love and sentiment in many countries around the world. (Photo by James D. Morgan/Getty Images)