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' 。
Several people complained of cat-like noises' at night and a businessman on a fishing trip saw the puma up a tree.
有人抱怨说夜里听见“像猫一样的叫声”;一位商人去钓鱼,看见那只美洲狮在树上。