Retroactivity
n. 追溯既往\\n[法] 溯及既往, 追溯效力
🗣️ 情景例句
I don't know. The baby-sitter says she has a stomachache,
我不知道。临时保姆说她肚子疼.
If you run after two heares, you will catch neither.
两头落空。
Inevitably the repair job was not quite so simple.
事实上，修理工作远不是那么简单。