Retroactivity
n. 追溯既往\\n[法] 溯及既往, 追溯效力
🗣️ 情景例句
You're most welcome.
不用客气。
The ox when weariest treads surest.
牛困走得稳。
She was a famous actress When I was still at school.
当我还是学生时，她就是个著名的演员了。