“Kids of Sapa”. Four little beautiful Hmong girls from Lao Chai Village, near Sapa, Vietnam. (Photo and caption by Felipe Hanower/National Geographic Traveler Photo Contest)

A youth stands near a cow and a sheep that were sacrified in the village of Miratovc for the celebration of Eid-al-Adha, near the town of Presevo, southern Serbia September 24, 2015. Muslims across the world celebrate the annual festival of Eid al-Adha or the Feast of the Sacrifice. (Photo by Hazir Reka/Reuters)

A man works on a small replica of the Iron Man armor next to a homemade replica of the “Hulkbuster” Iron Man armour from the movie “Avengers: Age of Ultron”, at an underground parking lot in Zhengzhou, Henan province, China, May 12, 2015. The 3.4-metre-tall replica is made of over 100 fiber-reinforced plastic components. It took Xing and his friends two months to put them together after watching the trailer of the movie in March, local media reported. (Photo by Reuters/Stringer)

A pupil of the Dao ethnic tribe returns home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)

People walk past debris on May 3, 2015 in Bhaktapur, Nepal. A major 7.8 earthquake hit Kathmandu mid-day on Saturday, and was followed by multiple aftershocks that triggered avalanches on Mt. Everest that buried mountain climbers in their base camps. (Photo by David Ramos/Getty Images)

Ivy on a house in North Queensferry, UK begins to turn from green to red as autumn draws nearer on August 26, 2024. (Photo by South West News Service)

This picture taken on October 18, 2018 shows a “trolley boy” pushing a home- made cart along a train track in Manila, Philippines. Scores of commuters in the city of about 12 million are propelled to their destinations daily by so-called “trolley boys” pushing metal carts that ply a few segments of the sprawling capital's railroads. (Photo by Noel Celis/AFP Photo)

Workers work inside a new Antonov airplane at the Antonov aircraft plant in Kiev, Ukraine, September 7, 2015. State-run aircraft maker Antonov built more than 22,000 units of more than one hundred types and modifications of passenger, transport and special-purpose aircraft, including the world's biggest cargo plane Antonov-225 (Mriya), according to the company's official website. (Photo by Gleb Garanich/Reuters)