A man walks on the road between Nouahibou and Nouakchott, where three Spanish aid workers were abducted in Mauritania, December 3, 2009. (Photo by Rafael Marchante/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)

The Aurora Borealis (Northern Lights) lights up the sky near the village of Pallas (Muonio region) of Lapland, Finland September 8, 2017. (Photo by Alexander Kuznetsov/Reuters/All About Lapland)

A worker unloads fish from a taxi boot at a fish market in Kolkata, India on February 5, 2018. (Photo by Rupak De Chowdhuri/Reuters)

Canadian actress Ellen Page and wife Emma Portner arrive at “The Cured” – Los Angeles Special Screening on February 20, 2018 at AMC Dine-In Sunset 5 in West Hollywood, CA. (Photo by Parisa Michelle/Splash News and Pictures)

Chinese model Ming Xi falls down on runway during the 2017 Victoria's Secret Fashion Show at Mercedes-Benz Arena on November 20, 2017 in Shanghai, China. (Photo by VCG/VCG via Getty Images)

People are caught in a dust storm in New Delhi, India May 23, 2016. (Photo by Anindito Mukherjee/Reuters)

A young boy plays with soap bubbles near Hofburg Palace at Heldenplatz, one of the top tourists attractions in Vienna, Austria, January 26, 2016. (Photo by Christian Bruna/EPA)