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)

ESA astronaut Samantha Cristoforetti on the International Space Station 3 February 2015 during her Futura mission. Samantha is living and working on the Station as part of the Expedition 42 crew. Picture released on February 10, 2015. (Photo by ESA/NASA)

An young Indian Jain devotee dressed as Lord Krishna participates in a religious rally organised on the occasion of Mahavir Jayanti in Kolkata on April 2, 2015. The most important religious holiday in Jainism, Mahavir Jayanti celebrates the birth of Mahavira, the last Tirthankara, which is generally accepted as 599 BCE. (Photo by Dibyangshu Sarkar/AFP Photo)

This combination of two photos taken on July 5, 2014, shows the Aazzab family waiting to break their fast, top, and their meal, bottom, during the holy month of Ramadan in Casablanca, Morocco. For the millions of Muslims abstaining from food and drink from sunrise to sunset every day during Islam's holiest month of Ramadan, that first sip of water after a grueling fast is by far the most anticipated moment of the day. (Photo by Abdeljalil Bounhar/AP Photo)

A child walks to an installation made from fallen leaves by college students, in shape of a sofa, to call for people's attention to environment protection, in Hangzhou, Zhejiang province, China, December 6, 2016. (Photo by Reuters/China Daily)

A vervet monkey passes in front of a woman on the shores of lake Naivasha, Kenya January 24, 2017. (Photo by Goran Tomasevic/Reuters)

A girl poses in her costume during a Halloween party at a mall in Quezon city, Metro Manila October 24, 2015. (Photo by Ezra Acayan/Reuters)

A plastinated body presented as a pole vaulter is exhibited at the Menschen Museum, Museum of Humans, in Berlin, August 29, 2016. The museum was caught up in a legal dispute with the district office of Berlin-Mitte for years before it was able to meet the requirements made by the court. (Photo by Sophia Kembowski/DPA Photo via Newscom)