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' 。
Country people run wild when they go shopping in the city and stagger home loaded with as many of the exotic items as they can carry.
乡里人进城采购欣喜若狂,每次回家时都买足了外来商品,直到拿不动方才罢休,连走路都摇摇晃晃的。