File photo taken in May of 1978 shows children taking part in a game of tug-of-war competition at a kindergarten in Sanmenxia City, central China's Henan Province. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades. (Xinhua)

File photo taken in June of 1979 shows children practicing dance skills at the children's art troupe in Shanghai, east China. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades. (Xinhua)

File photo taken on June 1, 1980 shows children celebrating the International Children's Day at Jingshan Park in Beijing, capital of China. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades. (Xinhua/Gu Dehua)

File photo taken in August of 1981 shows children's reaction when being checked their hands after cleaning at a kindergarten in north China's Inner Mongolia Autonomous Region. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades.(Xinhua/Tang Maolin)

File photo taken in July of 1982 shows children playing computer games at the China National Children's Center in Beijing, capital of China. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades. (Xinhua/Yang Shaoming)

File photo taken in September of 1983 shows children performing at the opening ceremony of the 5th Chinese National Games in Shanghai, east China. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades.(Xinhua/Zhang Liuren)

File photo taken on Oct. 1, 1984 shows children celebrating the National Day in Beijing, capital of China. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades. (Xinhua/Wang Xinqing)

File photo taken in 1985 shows children reading in the field in Sanchuan Township of Cangxi County, southwest China's Sichuan Province. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades. (Xinhua/Sun Zhongjing)

File photo taken in February of 1986 shows children making a snowman in Beijing, capital of China. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades. (Xinhua/Xia Yang)

File photo taken in March of 1987 shows children painting at Experimental Primary School in Suining County, east China's Jiangsu Province. This set of 41 old photos, taken from 1978 to 2018 by year, pictorially record childhood moments of Chinese kids in the past four decades. (Xinhua/Zhang Xun)