“Thunderstruck”. Summer stom. A super cell formed off the coast of New Zealand, intensified and swept across Christchurch and North Canterbury, February 23, 2014. Photo location: Christchurch, New Zealand. (Photo and caption by David Hardy/National Geographic Photo Contest)

Animal rights activists covered with fake blood sit on the floor during a protest against the use of animals in research to mark World Day for Animals in Laboratories in central Madrid April 24, 2014. The sign reads, “How many rabbits do your shampoo kill?”. (Photo by Andrea Comas/Reuters)

Balinese girls in traditional costumes gather during a parade for this year's last sundown in Bali island, Indonesia Thursday, December 31, 2015. (Photo by Firdia Lisnawati/AP Photo)

Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

The villas of Marabe Al Dhafra in Abu Dhabi, United Arab Emirates are home to approximately 2,000 people. Located in one of the hottest regions of the world, the record high temperature here is 49.2C° (120.6F°). (Photo by Benjamin Grant/Penguin Random House)

Fan Bing Bing, Concha de Plata (Silver Shell) award winnerfor best actress for the feature film “I Am Not Madame Bovary” speaks on her telephone during the awards ceremony at the San Sebastian Film Festival, September 24, 2016, in San Sebastian, northern Spain. (Photo by Vincent West/Reuters)

A dog from the K9 Division of the Sri Lanka Army’s Commando Regiment performs during an event to mark International Children’s Day at a school in Welisara, Colombo, Sri Lanka, 01 October 2016. Sri Lanka marks the Children's Day on 01 October with more emphasis on prevention of child abuse. (Photo by M.A. Pushpa Kumara/EPA)

Russian artist Maria Gasanova adjusts her make-up as she finishes “The Siberian Beauty” body art work from her “The Alive Painting” series before the opening ceremony of the Cultural Universiade as part of preparation for the 2019 Winter Universiade Krasnoyarsk, in the Siberian city of Krasnoyarsk, Russia, December 9, 2016. (Photo by Ilya Naymushin/Reuters)