Zd
n. 天顶距（zenith distance）；零色散（Zero Dispersion）
🗣️ 情景例句
My wife Marilyn, my father and mother,
我太太Marilyn， 我父亲和母亲，
Track 4 at 9:30.
9点30分，4轨道的车。
I don't know why he's in a tailor's shop. Just look at his clothes!
真不懂他为什么进服装店。瞧他这身打扮！