Cdh
abbr. constant differential height 常微分顶点
🗣️ 情景例句
I see him on the train every day but we are not on speaking terms.
我每天都在火车上见到他，但彼此没有说过话。
True love kythes(=shows itself)in time of need.
患难显真情。
I'm sorry I don't know. You'd better ask that policeman over there.
对不起，我不知道。你最好问问那边的警察。