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' 。
Once on the boat, they were taken bolow and their chains were fixed to two bars that ran the length of the ship.
一上船,他们就被带进底舱,他们的镣铐就被拴在两根从船的一头伸到另一头的铁杆上。