Black hair doesn't know how to study hard early, and white hair regrets how to study hard late. -Yan Zhenqing Young people are too old to learn, and one inch of time cannot be light. -Zhu A young man who doesn't work hard feels sorry for an old man. -"Long song", an old horse is full of ambition; Martyrs are full of courage in their twilight years. -Cao Cao, who never returns in his prime, will never get up again in the morning. Encourage yourself in time, and time waits for no one. -Tao Qian, heaven and earth, the journey of all things; Time flies, a passer-by for generations. -Li Bai, time flies and makes people old, and the sun and the moon run like teenagers. -smart, the deceased is like a husband, and he will not give up day and night. -Kong Qiu, tomorrow is tomorrow, there are so many tomorrows, I will wait for tomorrow, and everything is in vain. If the world is tired of tomorrow, it will go to Qiu Lai in spring to watch the water flow eastward.