China's population is aging at unprecedented levels. 使中国人口老龄化达到了前所未有的水平。
Though the US is not immune to population aging, its higher level of fertility combined with immigration gives it an enormous advantage. 美国并非不会受到人口老龄化的影响,但高水平的生育率加大量的移民给其带来巨大的优势。