请教各位Only when后面的内容是充分条件么？

teddyabc

Rt,127. Anthropologists assertthat cultures advance only when independence replaces dependence.是independence—>culture adavance吧？feifei里的是写CA——>independence，应该是哪一种呢？请教各位，谢谢！

xiexiang

是必要条件。
只有独立了才有cultures advance ，不代表独立了就一定有cultures advance ，cultures advance 建立在独立的基础上，因此independence为必要条件。

ddwantsmba

The phrases (then, only, only if, only when, must, required, unless, except, without, until) introduce a necessary condition.

The phrases (if, when, whenever, every, all, any, people who, in order to) introduce a sufficient condition.

teddyabc

恩好的，谢了！