If you don't know a person's last name, use 'ma'am' or 'sir'.
如果你不知道一人的姓, 你应称呼他为 'ma'am' 或 'sir' 。
I've got a lot of things to do before I can leave.
在我能离开以前,我有很多事情做。
Nothing can be compared, he maintains, with the first cockcrow, the twittering of birds at dawn, the sight of the rising sun glinting on the trees and pastures.