A vendor prepares paan, a betel nut-based chewable stimulant at a flower market in Kolkata, India, January 18, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A Palestinian boy herds sheep in front of the ruins of Yasser Arafat International Airport, which was bombed by Israel in the past, in Rafah in the southern Gaza Strip February 5, 2016. Nabil Shurafa's travel agency in Gaza was once packed with clients booking flights to London, Paris, New York or cities across the Arab world. These days, he's lucky if anyone comes in, as so few people can get out. (Photo by Ibraheem Abu Mustafa/Reuters)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

A Monster Jam truck performs a back flip during the first-ever monster truck event in Beijing's iconic “Bird's Nest” National Stadium on Saturday, July 29, 2017. (Photo by Ng Han Guan/AP Photo)

Members of the China Disabled Peoples Performing Art Troupe perform “My Dream” at Jorge Eliecer Gaitan Theater in Bogota on August 30, 2017. China Disabled People's Performing Art Troupe Company composed of artists with some hearing, mental, motor, visual or speech disabilities, was founded in 1987 and is currently Honorary and Goodwill Ambassadors of Unesco for its great example of inclusion. (Photo by John Vizcaino/AFP Photo)

A Boeing 777-300 from Swiss International Airlines lands on a foggy morning at Zurich Airport, on Friday, October 13, 2017, in Zurich, Switzerland. The high humidity renders the air vortex visible. (Photo by Christian Merz/Keystone via AP Photo)

People fancy dressed as “Catrina” take part in the “Catrinas Parade” along Reforma Avenue, in Mexico City on October 22, 2017. Mexicans get ready to celebrate the Day of the Dead highlighting the character of La Catrina which was created by cartoonist Jose Guadalupe Posada, famous for his drawings of typical local, folkloric scenes, socio- political criticism and for his illustrations of “skeletons” or skulls, including La Catrina. (Photo by Ronaldo Schemidt/AFP Photo)

A mahout guards the elephants during the annual Vrischikolsavam festival, which features a colourful procession of decorated elephants along with drum concerts, at a temple in Kochi, India, November 18, 2017. (Photo by Sivaram V/Reuters)