grand duke

例句：

1. 1.The grand duke of Cambridge is a famous figure in British history.
   剑桥公爵是英国历史上著名的人物。
2. 2. He was the grand duke of the kingdom during his reign.
   在他统治期间，他是王国的公爵。
3. 3.The grand duke's daughter is now a successful actress.
   公爵的女儿现在是一位成功的女演员。