A Tibetan nomad family crowds on a motorcycle at a camp for cordycep pickers on May 21, 2016 near Sershul on the Tibetan Plateau in the Garze Tibetan Autonomous Prefecture of Sichuan province. (Photo by Kevin Frayer/Getty Images)

A Pakistani vendor tries to salvage materials after flood water destroyed his shop following heavy rain on the outskirts of Peshawar on April 4, 2016. (Photo by A. Majeed/AFP Photo)

Palestinian woman Jihan Abu Muhsen prepares her donkey with her son Kareem before going work collecting bricks for sale from sites of demolished buildings, at her dwelling in Khan Younis in the southern Gaza Strip March 8, 2016. Abu Muhsen gathers bricks from the sites of demolished buildings and sells them to recycling factories. She earns around 20 shekels ($5) a day and her 10-year-old son Mohammad helps her when he is not at school. (Photo by Ibraheem Abu Mustafa/Reuters)

British visitors wearing Bavarian costumes walk ahead the opening of the traditional Bavarian Oktoberfest festival at the Theresienwiese in Munich, southern Germany, on September 20, 2014. Germany's world-famous Oktoberfest kicks off with millions of revellers set to soak up the frothy atmosphere in a 16-day extravaganza of lederhosen, oompah music and, of course, beer. (Photo by Karl-Josef Hildenbrand/AFP Photo/DPA)

Afghan girl athletes perform Wushu on the top of a hill in Kabul, capital of Afghanistan, January 18, 2017. In the conservative Afghan society where people especially in the countryside deeply believe in the old traditions and don't allow their girls and female members of the family to go out of home, exercising sport in open is extremely risky, but a group of girls are broken the taboo and exercising Wushu on a hilltop where the temperature is minus 2 Celsius degrees. (Photo by Rahmat Alizadah/Xinhua/Barcroft Images)

The waning moon sets behind leafless sumac trees on a crisp, clear morning, Thursday, December 15, 2016, in Portland, Maine. Much of the northern Mid-Atlantic and Northeast will stay cold for the next couple of days as the arctic air remains stuck over the northern Appalachians, the National Weather Service said. (Photo by Robert F. Bukaty/AP Photo)

A man pours water on his camel on a hot summer day in Ahmedabad, India, May 18, 2017. (Photo by Amit Dave/Reuters)

Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)