Fighters from the Democratic Forces of Syria prepare their weapons in the southwestern countryside of Hasaka, Syria February 17, 2016. Picture taken February 17, 2016. (Photo by Rodi Said/Reuters)

A paramilitary police officer (right) turns around as hostesses line up for roll call ahead of the Beijing International Automotive Exhibition in Beijing, China, on Monday, April 25, 2016. Tesla Motors Inc. and BYD Co. are among manufacturers showing 147 new-energy vehicles at this year's show. (Photo by Qilai Shen/Bloomberg)

Indian Hindu devotees carry an idol of the elephant-headed Hindu deity Ganesha for immersion in a temporary pond near Sangam in Allahabad on September 4, 2017. The Ganesh Chaturthi festival is a popular 11-day religious festival which is annually celebrated across India. (Photo by Sanjay Kanojia/AFP Photo)

A Catholic priest blesses a grave, marking All Saints' Day as the people stand next to monument partially destroyed by an old fallen tree at a cemetery in the village of Zubkovo, 150 km (93 miles) west of Minsk, Belarus, Wednesday, November 1, 2017. Belarusian Catholics marked All Saints Day by visiting graves of their relatives. (Photo by Sergei Grits/AP Photo)

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)

Mystical Forest. Tracey Jennings photographed this seven-gill shark in a kelp forest just off the shore of Simon's Town near Cape Town, South Africa. You don't need to travel far from cities to visit Narnia. This 7 gill shark was photographed in a kelp forest just off the shore of Simonstown near Cape Town, South Africa. (Photo by Tracey Jennings/National Geographic Travel Photographer of the Year Contest)

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

Bronze medalist Carlos Coloma Nicolas of Spain celebrates after finishing third in the cross-country cycling mountain bike race at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Saturday, August 20, 2016. (Photo by Patrick Semansky/AP Photo)