population ageing

population ageing读音音标

population ageing意思解释

英英释义

Population ageing is a phenomenon that occurs when the median age of a country or region rises due to rising life expectancy and/or declining birth rates. There has been, initially in the more economically developed countries ( MEDC ) but also more recently in LEDCs ( less economically developed countries ), an increase in the life expectancy which causes ageing population.