In this Thursday, May 8, 2014 photo, Iranian coal miners push metal carts to be loaded with coal at a mine near the city of Zirab 212 kilometers (132 miles) northeast of the capital Tehran, on a mountain in Mazandaran province, Iran. International sanctions linked to the decade-long dispute over Iran's nuclear program have hindered the import of heavy machinery and modern technology in all sectors, and coal mining is no exception. (Photo by Ebrahim Noroozi/AP Photo)

“Misty Morning”. Every morning, people expect sunny weather. Photo location: Bali, Indonesia. (Photo and caption by Henry Adam/National Geographic Photo Contest)

Syrian refugee boys play with toy guns at Eminonu district in Istanbul, Turkey, 08 January 2019. (Photo by Sedat Suna/EPA/EFE)

Women are reflected on silver panels of the French luxury brand Louis Vuitton flagship store at the Central Business District in Beijing, Wednesday, March 6, 2019. China will bar government authorities from demanding overseas companies hand over technology secrets in exchange for market share, a top economic official said Wednesday, addressing a key complaint at the heart of the current China-U.S. trade dispute. (Photo by Andy Wong/AP Photo)

Revellers out in Blackpool, Lancashire, United Kingdom on New Year's Eve, December 31, 2018. (Photo by Lorne Campbell/Guzelian)

A brick factory workers stack bricks on carts in Dhaka, Bangladesh, January 9, 2019. (Photo by Mohammad Ponir Hossain/Reuters)

These men are chased by the defiant elephants on May 4, 2013. Taken by Biplab Hazra in Bishnupur, India, the images show the extreme lengths the inhabitants of the town go to to deter elephants from damaging their crops and property. Elephants encroaching out of their habitats is an increasingly common occurrence with deforestation in much of India. (Photo by Biplab Hazra/Caters News Agency)

People stand in front of an murals at Lodhi Art District in New Delhi on March 24, 2019. Visitors throng Lodhi colony which has murals by dozens of Indian and international artists. (Photo by Sajjad Hussain/AFP Photo)