孜孜不倦

例句：

1. 1.He is a man of great persistence and perseverance, always striving for excellence.
   他是一个非常有毅力和坚持的人，总是追求卓越。
2. 2. The student was so diligent that he never stopped working even when tired.
   这个学生非常勤奋，即使累了也从不停止工作。
3. 3. She has been working tirelessly to improve the quality of her work.
   她一直在努力提高工作的质量。