This is a very common question, but I think give answer is very easy, if really wanna explain is quite difficult.

有个很普通的问题，回答容易，若要解释却很难。

youdao

This is a very common question, but I think give answer is very easy, if really wanna explain is quite difficult.

有个很普通的问题，回答容易，若要解释却很难。

youdao