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' 。
As a great many people will be visiting the country, the government will be building new hotels, an immense stadium, and a new Olympic-standard swimming pool.
由于将有大批的人到我们国家来,所以政府准备建造一些新的饭店、一个大型体育场和一个新的奥运会标准游泳池。