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' 。
However you decide to spend your time, one thing is certain: you will arrive at your destination fresh and uncrumpled.
不管你打算如何消磨时间,有件事是可以肯定的,即当你抵达目的地时,你感到精神焕发,毫无倦意,