Unity spreads the easy way of human communication. God in Bible punished people through the diversity of language and the tower of Babel fell apart imediantely because of the non-union language. From chinese more than 5000 historys, our coutry truly become the warm bed of corlorful culture. The difference of accents in different part of China are not understandable to every reginal citizens, like Cantonese to Beijingers and Shanghai dialect to Hongkongers. For that, mandarine steps into the historical stage. It is known that same interests will organize people as a group which now we call sub-culture circle,blood relationship will form the unite of family, same dialects will create a village or city... so how a same offical accent or dialect will performence its function? Here European Union could be a fine example. Most of them made a inherence of Roma, which we can find in their using latin characters. But Roma empire flashed in history river, leaving those European coutries attack each other, especially during the outbreak of COVID-19, like German rubbed the masks of Italy buying from China. This is the pathatic of Roma empire. Dialects truely flourish our live. But when we focus on public places, maybe dialects shoul be muted and this is what we china is doing now. One accent or dialect in public places take the quicker speed for human communication and union people's thinking, or China has already peacefully evoluted by USA.