A Palestinian man walks down snow-covered stairs after Friday prayers near the Dome of the Rock on the compound known to Muslims as Noble Sanctuary and to Jews as Temple Mount, in Jerusalem's Old City February 20, 2015. Snow covered Jerusalem and mountainous areas of Israel early Friday morning and the education ministry closed schools for the day. (Photo by Ammar Awad/Reuters)

In this Wednesday, March 18, 2015 photo, limestone quarry workers walk through a cloud of dust spewed into the air by rotor blades of the stone-cutting machinery in the desert of Minya, southern Egypt. Around 45,000 people, including children, work in an estimated 1,500 quarries, digging out stones that later will be used in construction or powdered to be used by pharmaceutical and ceramic companies. (Photo by Mosa'ab Elshamy/AP Photo)

A Buddhist nun walks along a path as a stupa is seen at a temple in Anuradhapura, Sri Lanka October 16, 2016. (Photo by Dinuka Liyanawatte/Reuters)

A truck driver cleans the mirror of his decorated truck in Charsadda outside Peshawar, Pakistan October 18, 2016. (Photo by Fayaz Aziz/Reuters)

A fuel cell electric vehicle (FCEV) by Nissan is shown at China (Guangzhou) International Automobile Exhibition in Guangzhou, China November 18, 2016. (Photo by Bobby Yip/Reuters)

A woman walks past a caricature of Britain's Foreign Secretary Boris Johnson in east London, Britain November 18, 2016. (Photo by Andrew Winning/Reuters)

A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. (Photo by Reuters/NASA/ESA/Hubble)

A woman, wearing a traditional Sevillana dress, performs as she asks for alms in downtown Malaga, Spain, April 28, 2016. (Photo by Jon Nazca/Reuters)