Students attend a stewardess skill training for the upcoming 2017 entrance examination for art majors in colleges in Luoyang, central China's Henan Province, January 4, 2017. Along with how to stand, how to sit is also covered in these classes. (Photo by Li Bo/Xinhua/Barcroft Images)

Emily Ratajkowski is seen at “Jimmy Kimmel Live” on August 07, 2017 in Los Angeles, California. (Photo by Rex Features/Shutterstock)

A woman dressed up for Halloween travels on a Metro train in São Paulo, Brazil on October 30, 2017. (Photo by Cris Faga/Rex Features/Shutterstock)

A worker applies colour to strings which will be used to fly kites, by a roadside in Ahmedabad, India, November 23, 2017. (Photo by Amit Dave/Reuters)

Bella Hadid arriving at her hotel on December 7, 2017 in London, England. (Photo by Palace Lee/PacificCoastNews)

A soldier walks on the bank of the river in central Pyongyang, North Korea on April 16, 2017. (Photo by Damir Sagolj/Reuters)

An angler fishes on the opening day of the salmon fishing season on the River Tay at Kenmore in Scotland, Britain January 16, 2017. (Photo by Russell Cheyne/Reuters)

A visitor feeds a food pellet to a giraffe in the Giraffe Centre in Nairobi, Kenya January 15, 2017. (Photo by Goran Tomasevic/Reuters)