A woman touches a robot at the 2018 World Robot Conference in Beijing on August 15, 2018. The conference will be held from 15 to 19 August and will include a conference on robotics, an exhibition and a robot competition with the participation of robotics enterprises to showcase their robot products. (Photo by Wang Zhao/AFP Photo)

Woman on swings attached to a float during the Sexual Freedom Parade, part of Naughty in N'awlins held in New Orleans, Louisiana, Wednesday July 5th, 2017. These are the photos from inside the world’s largest swinging convention for couples. The exclusive images reveal the unlikely couples who like to engage in sexual relations with other people besides their partners – and show that swinging is more ‘normal’ than you think. (Photo by Mathew Growcoot/News Dog Media)

Enya Kim from the Natural History department at auctioneers Bonhams & Butterfields stands in front of one of the world's largest set of shark jaws comprised of about 180 fossil teeth from the prehistoric species, Carcharocles megalodon, which grew to the size of a school bus, at the Venetian Resort Hotel Casino September 30, 2009 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)

A concept illustration of the world's first forest in the sky, the Bosco Verticale green twin towers currently under construction in Milan, Italy. Towering over the city skyline the world's first forest in the sky will be a sight to behold. With tree equal to one hectare of forest spanning 27 floors these 365 and 260 foot emerald twin towers will be home to an astonishing 730 trees, 5,000 shrubs and 11,000 ground cover plants. (Photo by Boeri Studio)

A vendor prepares paan, a betel nut-based chewable stimulant at a flower market in Kolkata, India, January 18, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A guest poses with a magic wand during a soft opening and media tour of “The Wizarding World of Harry Potter” theme park at the Universal Studios Hollywood in Los Angeles, California in this picture taken March 22, 2016. (Photo by Kevork Djansezian/Reuters)

Beyonce performs during the Formation World Tour at Raymond James Stadium on Friday, April 29, 2016, in Tampa, Florida. (Photo by Frank Micelotta/Invision for Parkwood Entertainment/AP Images)

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)