What's good about giving the teacher a pair of calligraphy?

Catch me, and I'll catch you.

There are students everywhere; There are students all over the country [the world].

Silkworms in spring will weave until they die, and candles will drain the wick every night.

The crane sends silver silk to reflect the sun and the moon, and its efforts are full of new flowers.

Once a teacher, always a father.

A gift from a paragraph is also my teacher.

Sneak into the night with the wind, moisten things silently.

Tufeiligula

What's the use of learning and teaching?