A migrant boy sits on railway tracks at a train station in Tovarnik, Croatia, September 20, 2015. (Photo by Antonio Bronic/Reuters)

A dune buggy driver trains before competing in a sand dune drag racing event on January 8, 2016, as part of the Liwa 2016 Moreeb Dune Festival in the Liwa desert, some 250 kilometres southwest of Abu Dhabi. The festival, which attracts participants from around the Gulf region, includes a variety of races (cars, bikes, falcons, camels and horses) or other activities aimed at promoting the country's folklore. (Photo by Karim Sahib/AFP Photo)

Students exercise in body training at Bishan Vocational Education Center in Chongqing, southwest China, January 13, 2016. These students were trained to be stewardesses of the high-speed train. (Photo by Xie Jie/Xinhua)

A man dressed as a “Trapajon”, representing entities of nature, poses for a picture after taking part in the Vijanera Festival in Silio, northern Spain, Sunday, Jan. 6, 2013. The Vijanera masquerade, of pre-Roman origin, is the first carnival of the year in Europe symbolizing the triumph of good over evil and involving the participation of crowds of residents wearing different masks, animal skins and brightly colored clothing with its own complex function and symbolism and becoming the living example of the survival of archaic cults to nature. (Photo by Daniel Ochoa de Olza/AP Photo)

Children try to push an injured and weak dolphin back into the water after it washed ashore during bad weather and high tide on a beach in Cilacap, Central Java, Indonesia August 12, 2016 in this photo taken by Antara Foto. (Photo by Idhad Zakaria/Reuters/Antara Foto)

Germany's Wolfgang Kimmig-Liebe, who has been volunteering as Santa Claus for years, is searched by a Carabiniere paramilitary police officer before entering in St. Peter's Square at the Vatican to attend Pope Francis general audience, Wednesday, December 2, 2015. (Photo by Alessandra Tarantino/AP Photo)

Models present Victoria Secret Fantasy Bras priced at $2 million each during a media preview of the Singapore JewelFest in Singapore October 8, 2015. The festival which is in its 13th year, sees over 42 Asian designers participating and over $300 million worth of jewels for sale. It opens from October 9 to 18. (Photo by Edgar Su/Reuters)

Russia's Ekaterina Birlova casts a shadow on the sand as she serves to Poland during a women's beach volleyball match at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Tuesday, August 9, 2016. (Photo by Marcio Jose Sanchez/AP Photo)