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)

Family of passengers onboard AirAsia flight QZ8501 react at a waiting area in Juanda International Airport, Surabaya December 28, 2014. Indonesia's air force was searching for the AirAsia plane carrying 162 people that went missing on Sunday after the pilots asked to change course to avoid bad weather during a flight from the Indonesian city of Surabaya to Singapore. The Airbus 320-200 lost contact with Jakarta air traffic control at 6:17 a.m. (23:17 GMT), officials said. (Photo by Reuters/Beawiharta)

A handout picture provided by the press service of MORTON Group of Companies, show the balloon of Russian adventurer Fedor Konyukhov in the sky during his solo round-the-world balloon flight just after taking off from a spot near Northam, 96 kilometres north-east of Perth in Western Australia, 12 July 2016. Fedor Konyukhov took off from Northam on 12 July 2016 in attempt to beat the record of 13 days of American aviator Steve Fossett. (Photo by EPA/Morton Press Service)

Hotel guides jump as they pose for pictures outside the Great Hall of the People during the opening session of the National People's Congress (NPC) in Beijing, China, March 5, 2016. (Photo by Aly Song/Reuters)

A Chinese bus ushers jump as she pose for a photograph on Tiananmen Square during a plenary session of the National People's Congress held at the Great Hall of the People in Beijing, Wednesday, March 9, 2016. (Photo by Andy Wong/AP Photo)

A participant plays a game on her phone as others watch during a break in a traditional Chinese opera competition at the National Academy of Chinese Theatre Arts in Beijing, China, November 26, 2016. (Photo by Thomas Peter/Reuters)

Folk artist Han Xiaoming demonstrates painting with his tongue in Hangzhou, Zhejiang province December 4, 2014. Han dips his tongue in ink to paint on paper, and uses his fingers to fill in final adjustments. The artist also uses a paintbrush held with his mouth and utilizes fish and vegetables as paint tools, local media reported. (Photo by Aly Song/Reuters)