Activists from People for the Ethical Treatment of Animals (PETA) promoting a vegan diet are pictured as people drive past in Los Angeles, California May 21, 2015. (Photo by Mario Anzuoni/Reuters)

An instructor (C) adjusts the posture of students of flight attendant major during a training session at Anhui Foreign Languages University, in Hefei, Anhui province, China, May 25, 2015. (Photo by Reuters/China Daily)

Labourers work at the installation site of Liquefied Petroleum Gas (LPG) pipeline on May Day or Labour Day in Chandigarh, India, May 1, 2015. (Photo by Ajay Verma/Reuters)

Female soldiers with their faces painted in the colours of the Venezuelan flag, march during a military parade to celebrate the anniversary of Venezuela's independence in Caracas, July 5, 2015. (Photo by Jorge Dan Lopez/Reuters)

A group of costumed fans attend Comic-Con International at San Diego Convention Center on July 12, 2015 in San Diego, California. (Photo by Daniel Knighton/Getty Images)

The pit lane is reflected in the visor of a Mercedes Formula One pit crew member during the second practice session of the Australian F1 Grand Prix at the Albert Park circuit in Melbourne March 13, 2015. REUTERS/Brandon Malone

A man with a painted face and traditional costumes takes part in the Schleicherlaufen festival in the western Austrian town of Telfs February 1, 2015. (Photo by Dominic Ebenbichler/Reuters)

A masked reveller poses near Saint Mark's Square during the Venetian Carnival in Venice January 31, 2015. (Photo by Stefano Rellandini/Reuters)