In order to let his son study well, the famous Han Yu of the Tang Dynasty wrote a poem "Fu Reading Chengnan" to introduce the benefits of reading. The content of the verse is to say that two children, one is eager to learn and the other is bored. child

In order to let his son study well, the famous Han Yu of the Tang Dynasty wrote a poem "Fu Reading Chengnan" to introduce the benefits of reading. The content of the verse is to say that two children, one is eager to learn and the other is bored. As the child grows up, the difference between the two gradually becomes clear. At the age of 20, the difference is like a clear gutter and a sewage ditch. At the age of 30, one soared like a dragon and one crawled on the ground like a toad. This is an allusion to the idiom "flying yellow tengda", which is used as a metaphor for the rapid improvement of position or status.