Woman and man playing domination games in bed. (Photo by NDAB Creativity/Rex Features/Shutterstock)

Girls of University of Cincinnati Stage Grecian Games on April 29, 1921. Garbed in costumes of ancient Greece, fair students of the University of Cincinnati, Ohio arranged a set of Grecian Games for the benefit of the University athletic fund. All of the girl students of the University, who take a great interest in outdoor games and athletics, took part in the games. The fund was greatly increased through the staging of the unique attraction and the girls purpose to give a return engagement. The accompanying photographs show the girl contestants in their Grecian costumes. Photo shows the start of the 100 yard dash. (Photo by Bettmann Archive/Getty Images)

A police officer reacts to flames during a protest against Chile's government in Santiago, Chile on November 4, 2019. Unrest began in Chile last October 18 with protests against a rise in transport tickets and other austerity measures and descended into vandalism, looting, and clashes between demonstrators and police. Protesters are angry about low salaries and pensions, poor public healthcare and education, and a yawning gap between rich and poor. (Photo by Henry Romero/Reuters)

Liu Yi, Chinese painter, was born in Shanghai in 1958. He was a Fine Arts graduate from the Hua Dong University for Education. He did his postgraduate study of watercolor painting at the China College of Fine Arts. He lectures at university for painting and design. He is a member of the Chinese Artists Association and is also a member of the Watercolor Painting Artists Association. He is the retired Deputy President of the Shanghai Watercolor Painting Society, and is currently the Deputy Principal of the Shanghai Arts and Technical College. He is a very accomplished watercolor painter in China.

“RoboCup is an international robotics competition founded in 1997. The aim is to develop autonomous soccer robots with the intention of promoting research and education in the field of artificial intelligence. The name RoboCup is a contraction of the competition's full name, «Robot Soccer World Cup», but there are many other stages of the competition such as «Search and Rescue» and «Robot Dancing»”. – Wikipedia

Photo: Humanoid robots of the children size league compete during the RoboCup 2006 football world championships final at the Congress Centre on June 18, 2006 in Bremen, Germany. (Photo by Malte Christians/Bongarts/Getty Images)

A prototype of a new nano spaceship is displayed during a press conference held by Israel's Space IL organisation on December 8, 2011 in Ehud, Israel. Israeli President Shimon Peres participated in the event unveiling Space IL's latest prototype nano spaceship with the aim of launching a Israeli robotic spacecraft that will land on the moon and raise funds for scientific education in Israel. (Photo by Ilia Yefimovich/Getty Images)

In this Saturday, September 5, 2015, photo, three women in costumes look at sea life swimming above them during a private party held at the Georgia Aquarium as part of Dragon Con in Atlanta. The convention draws fans from around the country to take part in sci-fi and fantasy costume contests, a massive parade through downtown Atlanta and educational seminars about science and costume making. (Photo by Ron Harris/AP Photo)

A Palestinian man walks down snow-covered stairs after Friday prayers near the Dome of the Rock on the compound known to Muslims as Noble Sanctuary and to Jews as Temple Mount, in Jerusalem's Old City February 20, 2015. Snow covered Jerusalem and mountainous areas of Israel early Friday morning and the education ministry closed schools for the day. (Photo by Ammar Awad/Reuters)