Differentiating
[計] 微分的
??? 情景例句
It's no use crying over spilt milk. What's done cannot be undone.
覆水難收。
Marry your son when you will, your daughter when you .
給兒子娶親，想在什么時候皆可；把女兒嫁人要在有力量時才行。
When were you born?
你什么時候出生的？