File photo taken on May 29, 2010 shows children, most of whom are left-behind children with their parents working at big cities, taking part in a wheat-carrying game in Hekou Town, Huangshi City, central China's Hubei 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)