问一个短语的意思Shethrewoutalifejacket,asitwere,towomennotoncebuttwice,duringtwodistinctperiodsdecadesapart:the1920andthe1950s.alifenotoncebuttwice是不是指多次的意思？

Question

问一个短语的意思
She threw out a life jacket,as it were,to women not once but twice,during two distinct periods decades apart:the 1920and the 1950s.
a life
not once but
twice是不是指多次的意思？

Answer 1

a life jacket —— 救身衣
not once but twice —— 不是一次,而是两次
twice：两次