“left-behind elderly”的概念、定义、翻译、参考文献-科学参考

单词	left-behind elderly
释义	left-behind elderly Encyclopedia 法学老年社会问题释 left-behind elderly留守老人因子女离开而留在原家庭中的老年人。根据中国对人口迁移流动的定义，严格意义上的留守老人指因子女离开（跨越县级以上行政区）半年及以上而留守在家的老年人。
随便看	elementary permutation elementary pinning force elementary polymer elementary probability theory elementary proof elementary property elementary reaction elementary reaction of transition metal organic compound elementary reaction step elementary reduction elementary relations elementary renewal theorem elementary row and column operation elementary row operation elementary row transformation elementary sentence of locus elementary set elementary situation elementary solution elementary space elementary species elementary stage in fluid machinery design elementary state elementary strategy elementary subdivision

科学参考收录了854744条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。