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' 。
Over the next thirty-two years he fought for human rights and the rights of workers who were badly treated by their employers.
在后来的32年多的时间里,他一直为争取人权及那些受雇主虐待的工人们的权利而斗争。