left-behind children是什么意思

left-behind children 留守儿童短语：Entire Left-behind Children 完全留守儿童Rural left-behind children 农村留守儿童Preschool Left-behind Children 学前留守儿童例：Many of us have heard about the so-called left-behind children. 许多人都听到过所谓的留守儿童一