If you know a man's last name, address him as 'Mr.'.
如果你知道一个男性的姓, 应该用 'Mr。' 来称呼他。
While she always criticized the fickleness of human nature, she carried on an unrelenting search for the ideal servant to the end of her days,
她一方面总是批评人的本性朝三暮四,另一方面她又持之以恒地寻找一个理想的佣人。