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)

A street artist dances tango in Buenos Aires, Argentina, Tuesday, January 20, 2015. Tango is a partner dance that originated in the 1890's along the Rio de la Plata, the border between Uruguay and Argentina. UNESCO approved in 2009, a joint proposal by the two nations to include the dance in its Intangible Cultural Heritage List. (Photo by Rodrigo Abd/AP Photo)

Members of the “Avalon” team wearing 14th century knight costumes fight against each other on the bank of the Yenisei River during the regional amateurs tournament of clubs of historical reconstruction, “The Battle of the Nations 2015. Siberia”, in Krasnoyarsk January 24, 2015. (Photo by Ilya Naymushin/Reuters)

2016 Rio Olympics, Weightlifting, Final, Women's 48kg, Riocentro, Pavilion 2, Rio de Janeiro, Brazil on August 6, 2016. Beatriz Piron (DOM) of Dominican Republic fails to lift. (Photo by Kai Pfaffenbach/Reuters)

The 27 curvy candidates for this year's eagerly-awaited Miss Bumbum pageant showed off all their assets as they paraded on one of Sao Paulo's busiest streets – Avenida Paulista – for the launch promotional race on August 8, 2016. Unsurprisingly, they stopped traffic. The girls will be fighting it out for the coveted title in a public vote before being whittled down to 15 finalists for the grand finale in November. (Photo by Leo Marinho/Splash News and Pictures)

Revellers battle with tomato pulp during the annual “Tomatina” (tomato fight) festival in Bunol near Valencia, Spain, August 31, 2016. (Photo by Heino Kalis/Reuters)

Members of the association historical recreation Frente del Nalon participate in the recreation of the battle: “The Siege of Oviedo” that took place during the Spanish Civil War, in Grullos, near Oviedo, in northern Spain, September 3, 2016. The Siege of Oviedo lasted from July 19 until October 16, 1936. The town garrison, under the command of Colonel Antonio Aranda Mata, declared for the uprising and held out until relieved by a Nationalist force. (Photo by Eloy Alonso/Reuters)

Lulu, her Playa name, falls into a foam pit as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. September 1, 2016. (Photo by Jim Urquhart/Reuters)