老年人:senior citizens/the elderly

　　退休:retirement 退休金:pension

　　养老保险:endowment insurance

　　老龄化社会:aging society

　　计划生育:family planning

　　低出生率:low birth rate

　　空巢综合症:empty nest syndrome

　　孝顺:filial piety

　　孝子:dutiful son

　　长寿:longevity