A fuel cell electric vehicle (FCEV) by Nissan is shown at China (Guangzhou) International Automobile Exhibition in Guangzhou, China November 18, 2016. (Photo by Bobby Yip/Reuters)

A woman walks past a caricature of Britain's Foreign Secretary Boris Johnson in east London, Britain November 18, 2016. (Photo by Andrew Winning/Reuters)

A model wears a floral head dress as she promotes a chain of garden centres at the Royal Horticultural Soceity's Chelsea Flower Show in London, Britain, May 18, 2015. (Photo by Toby Melville/Reuters)

Competitors prepare backstage before the 2015 Brazil Miss and Mister Fitness contest in Sao Paulo, Brazil, June 18, 2015. Some 96 men and women from all across the country competed in the event. (Photo by Paulo Whitaker/Reuters)

A model presents a creation from Andres Sarda's Fall/Winter 2017 collection during the Mercedes-Benz Fashion Week in Madrid, Spain February 18, 2017. (Photo by Javier Barbancho/Reuters)

Daisy Lowe attends Maybelline's Bring On The Night Party on February 18, 2017 in London, United Kingdom (Photo by Jeff Spicer/Getty Images)

Eagle Prime (MK3), a giant robot by MegaBots Inc. which manufactures giant piloted humanoid fighting robots headquartered in Berkeley, California on October 18, 2017. (Photo by Courtesy Michael Mauldin/Reuters/MegaBots Inc)

A mahout guards the elephants during the annual Vrischikolsavam festival, which features a colourful procession of decorated elephants along with drum concerts, at a temple in Kochi, India, November 18, 2017. (Photo by Sivaram V/Reuters)