The complement system is a family of small proteins that work in an enzymatic cascade to fight off bacterial infections.

补体系统是一群小的蛋白质，以酶促级联的方式抵抗细菌感染。

China rolled out a private pension plan on Thursday to complement the nation's current pension system in its latest effort to tackle the strains of an aging population.

《国务院办公厅关于推动个人养老金发展的意见》周二公布。随着人口老龄化的加剧，推动个人养老金发展, 是对基本养老保险的有效补充。