First of all, games can be roughly divided into three needs, namely, residential needs, commercial needs and industrial needs. If there is commercial demand, the business district will be built, and if there is industrial demand, the industrial district and office district can be built, and the office district belongs to industrial demand. Secondly, the level of civic education needed in the business circle can range from primary school to university, while that needed in the industrial area is basically in primary school and middle school, which is basically not needed in universities (which is also the reason why many players set up illiterate communities in the later period), and the office area needs better education, and the city basically needs university graduates before it can set up an office area. Finally, generally speaking, if there is industrial demand in the early stage, an industrial zone will be established, and then an office zone will be established when there is a large population in the later stage. Finally, for the beauty of the city, the industrial zone can even be demolished, leaving only the office area, which is actually similar to the industrial upgrading in reality.