Cdh
abbr. constant differential height 常微分顶点
🗣️ 情景例句
Hello, I'm glad to meet you. I've heard so much about you.
你好， 很高兴见到你。 久仰， 久仰。
What time is the mail delivered on Saturday?
邮件在星期六什么时间被递送？
What about you?
你呢？