Zd
n. 天顶距（zenith distance）；零色散（Zero Dispersion）
🗣️ 情景例句
Go by the book.
照章办事。
He has forgotten about his job.
他把工作忘得一干二净。
The day after, Patrick went to the house once more and asked exactly the same question.
第三天，帕特里克又去了，提出了同前两天完全一样的问题。