Turbines of the new Burbo Bank off shore wind farm lay in the wake of a maintenance boat in the mouth of the River Mersey on May 12, 2008 in Liverpool, England. (Photo by Christopher Furlong/Getty Images)

This picture taken on December 31, 2017 shows an Indian sadhu preparing food at a camp at Sangam, ahead of the Magh Mela festival, in Allahabad. The Magh Mela, which is known as a mini-Kumbh Mela, is scheduled to start January 2 and continue until February 13 with auspicious bathing dates throughout the 45 day period. (Photo by Sanjay Kanojia/AFP Photo)

Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

Women labourers work at the construction site of a road in Kolkata January 8, 2015. Across towns and cities in India, it is not uncommon to see women cleaning building sites, carrying bricks and or shoveling gravel – helping construct the infrastructure necessary for the country's economic and social development. They help build roads, railway tracks, airports, and offices. They lay pipes for clean water supplies, cables for telecommunications, and dig the drains for sewage systems. But although women make up at least 20 percent of India's 40 million construction workers, they are less recognized than male workers with lower pay and often prone to safety hazards and sexual harassment. They are often unaware of their rights or scared to complain, say activists now trying to campaign for better treatment of women in the construction industry. (Photo by Rupak De Chowdhuri/Reuters)

A woman in traditional clothes wears a pin showing North Korea's founder Kim Il-sung (L) and former leader Kim Jong-il, on her dress as she welcomes foreign reporters to a temple during a government organised tour just outside Pyongyang October 8, 2015. North Korea is getting ready to celebrate the 70th anniversary of the founding of its ruling Workers' Party of Korea on October 10. (Photo by Damir Sagolj/Reuters)

A boat is stranded on Poyang Lake in Lushan City, China during low-water season on November 3, 2016. (Photo by Xinhua/Barcroft Images)

People walk past a New Year fir tree made of toys at a park in Krasnoyarsk, Siberia, Russia January 2, 2017. (Photo by Ilya Naymushin/Reuters)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)