Prospective flight attendants listen to their instructor during an etiquette training course at Indigo Airlines' Ifly training centre in Gurgaon on the outskirts of New Delhi November 18, 2014. (Photo by Adnan Abidi/Reuters)

Jan Kara (R) and Jan Holan pedal their boat, made with plastic bottles, on the Elbe river near Kostelec nad Labem July 15, 2014. Jan Kara, a 22-year-old student, and Jakub Bures, a 22-year-old car mechanic, built the 10-metre (32.8-feet) long boat from 5000 plastic bottles strapped to a wooden frame. (Photo by David W. Cerny/Reuters)

Egmont National Park in New Zealand with Mt. Taranaki at its center is seen in a Landsat 8 satellite image taken July 3, 2014 and released by NASA November 14, 2014. The image is from the book “Sanctuary: Exploring the World's Protected Areas from Space”, published by the Institute for Global Environmental Strategies with support from NASA, which was released this week. (Photo by Reuters/NASA/USGS)

A squirrel crawls along an electrical cable as a kingfisher takes off from it in New Delhi, India, October 24, 2020. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)

Fishermen carry calabashes to attend Argungu fishing and cultural festival at Argungu Town, Kebbi State in northwestern Nigeria, on March 14, 2020. Argungu fishing and cultural festival is one of the oldest and most widely attended festivals in the country dating back many generations, featuring series of water competitions and traditional games. The festival returned after 10 years suspension due to insecurity in northwest Nigeria. (Photo by Pius Utomi Ekpei/AFP Photo)

Crews prepare hot air balloons for the Kentucky Derby Festival Great Balloonfest Rush Hour Race at Bowman Field on Friday, April 26, 2024. (Photo by Michael Clevenger/Courier Journal)

Thousands of heavy-duty trucks loaded with coal are lined up for up to 130 kilometres from the Mongolia-China border on a sole road in the Gobi desert, Mongolia, October 29, 2017. The journey can take more than a week. (Photo by Bazarsukh Rentsendorj/Reuters)

“Mr Big Dipper”, Nicholas Roemmelt (Denmark). A stargazer observes the constellation of the Big Dipper perfectly aligned with the window of the entrance to a large glacier cave in Engadin, Switzerland. This is a panorama of two pictures, and each is a stack of another two pictures: one for the stars and another one for the foreground, but with no composing or time blending. (Photo by Nicholas Roemmelt/National Maritime Museum/The Guardian)