In this April 14, 2014 file photo, Hamamatou Harouna, 10, who lost the use of her legs to polio, crawls to the restroom on the grounds of the Catholic Church where she and hundreds of others found refuge after fleeing violence in her village, in Carnot, Central African Republic. Health authorities on Tuesday, August 25, 2020 are expected to declare the African continent free of the wild poliovirus after decades of effort, though cases of vaccine-derived polio are still sparking outbreaks of the paralyzing disease in more than a dozen countries. (Photo by Jerome Delay/AP Photo/File)

A Student of Yuba Pratibha School, wearing a face shield and masks at school during a coronavirus pandemic in Kathmandu, Nepal, 26 November 2020. The head Teacher of Yuba Pratibha School, Yanga Raj Dahal, started to conduct classes for students, who can’t afford and attend online classes, with strict sanitary regime, providing also free face masks and shields for students. However majority of schools have been conducting online classes in Nepal from 19 March 2020 as part of precautionary measures against the spread of the coronavirus Covid-19. (Photo by Narendra Shrestha/EPA/EFE)

A Funnel Web spider is pictured at the Australian Reptile Park January 23, 2006 in Sydney, Australia. The Funnel Web is one of Australia's deadliest animals, with a venom that is packed with at least 40 different toxic proteins. A bite from a Funnel Web causes massive electrical over-load in the body's nervous system. Finally, fatalities occur from either heart attack or a pulmonary oedema, where the capillaries around the lungs begin to leak fluid and the patient effectively drowns. Death can come as quickly as two hours after a bite if no medical treatment is sought. Due to advances in anti-venom, there has been no death from a Funnel Web bite in Australia since 1980. Australia is home to some of the most deadly and poisonous animals on earth. (Photo by Ian Waldie/Getty Images)

These adorable cats – which are twins – showcase their contrasting blue and green eyes. The cats have a condition called heterochromia iridis, which causes each eye to vary in color. (Photo by @sis.twins/Caters News Agency)

Bronze whaler shark (Carcharhinus brachyurus), caught in traditional seine net and released by fisherman, Muizenberg beach, Cape Town, South Africa on October 11, 2016. Action shots have captured fishermen trying to free a potentially deadly Bronze Whaler shark who was caught in their nets. The incredible images show the eight-foot-long 500-pound predator lunging its mouth towards the fishermen who are desperately trying to pull it back into the safety of the sea by its tail. Eventually they succeeded. (Photo by Chris and Monique Fallows/NPL)

A riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

Mackenzie Brown from the USA warms up on stage prior the final ofthe 47th Prix de Lausanne in Lausanne, Switzerland, 09 February 2019. Launched in 1973, the Prix de Lausanne is an international dance competition for young dancers. The best dancers will be awarded with scholarships granting free tuition in a world-renowned dance school or dance company. (Photo by Valentin Flauraud/EPA/EFE)

Specialist Dilip Patel, left, works at his post on the floor of the New York Stock Exchange, Monday, March 9, 2020. The Dow Jones Industrial Average sank 7.8%, its steepest drop since the financial crisis of 2008, as a free-fall in oil prices and worsening fears of fallout from the spreading coronavirus outbreak seize markets. (Photo by Richard Drew/AP Photo)