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)

Planes land in fog at Heathrow Airport, west London on January 4, 2014, as heavy fog covers a many parts of the south east. (Photo by Steve Parsons/PA Images via Getty Images)

Manuelle aka the Snake Woman poses for photographs with a beer as she promotes the fnnual Beer Festival Oktoberfest in Cologne, Germany on September 22, 2014. (Photo by Federico Gambarini/EPA/EFE/Rex Features/Shutterstock)

Model Ireland Baldwin attends NBC and Time Inc. celebrate the 50th anniversary of the Sports Illustrated Swimsuit Issue at Dolby Theatre on January 14, 2014 in Hollywood, California. (Photo by Dimitrios Kambouris/Getty Images)

Mulan Jamilah, a 6-year-old Bengal tiger, kisses caretaker Abdullah Sholeh, 33, in the garden beside their home on January 20, 2014 in Malang, Indonesia.

A woman photographs a Norwegian spruce Christmas tree from Oslo after it was lit at Trafalgar Square in central London, December 4, 2014. (Photo by Toby Melville/Reuters)

A performer from Cirque du Soleil's show “Quidam” practices backstage before a show at the MEO Arena in Lisbon December 18, 2014. (Photo by Rafael Marchante/Reuters)

Ukrainian servicemen sit atop an armored personnel carrier (APC) at a military base in the town of Kramatorsk, eastern Ukraine, December 24, 2014. (Photo by Valentyn Ogirenko/Reuters)