Members of the Gremlins Carnival Club, open the doors to their workshop to unveil for the first time their cart, Jungle Drums, which is their entry to this year's Bridgwater Carnival, on November 4, 2011 in Bridgwater, England. (Photo by Matt Cardy/Getty Images)

A woman views the Mummy of Meresamun in the Ashmolean Museum's new exhibition of artifacts from ancient Egypt and Nubia on November 23, 2011 in Oxford, England. The new gallery is displaying for the first time in decades some of the finest Egyptian and Nubian artifacts in the UK. The Egyptian collection opens to the public from November 26, 2011. (Photo by Oli Scarff/Getty Images)

A fan lies passed out on the first day of the Wacken Open Air heavy metal music fest on August 4, 2011 in Wacken, Germany. Approximately 75,000 heavy metal fans from all over the world have descended on the north German village of 1,800 residents for the annual three-day fest. (Photo by Sean Gallup/Getty Images)

A man shaves blocks of salt from the Danakil Depression on 28 March 2017, in Afar, Ethiopia. Every morning, hundreds of men converge on a dry lakebed in a remote corner of Ethiopia, where they cleave the ground open with handaxes to extract salt, just as their fathers and grandfathers once did. (Photo by Zacharias Abubeker/AFP Photo)

Subway passengers walk past bronze sculptures representing the Soviet people at the Ploshchad Revolyutsii metro station in Moscow, on November 14, 2012. The station was opened in 1938. (Photo by Kirill Kudryavtsev/AFP Photo)

Robot couple Xiaolan (L) and Xiaotao carry trays of food at a restaurant in Jinhua, Zhejiang province, China, May 18, 2015. The restaurant, which opened on Monday, has two robots delivering food for customers. The robots were designed as a couple, Xiaolan and Xiaotao, according to local media. (Photo by Reuters/Stringer)