1. The lights are on at three o'clock and the chicken is on at five o'clock. It's when men are studying. Black-haired people don't know how to study early, and white-haired people regret studying late. - Yan Zhenqing

2. An inch of time is worth an inch of gold, but an inch of gold cannot buy an inch of time.

3. It is easy for a young man to learn but hard to become an old man, and an inch of time cannot be taken lightly. - Zhu Xi

4. My life has its limits, but my knowledge has no limits. - Zhuangzi

5. If young people do not work hard, old people will be sad.

--"Long Song Xing"