1. Higher wages: Other educational institutions offer higher wages, which may have attracted Korea, Korea and Li Huan.
2. Career development: Korea and Li Huan may seek more career development opportunities in other educational institutions.
3. Inadaptability of institutional culture: Everyone has different degrees of adaptation to institutional culture, and may not adapt to political culture, so they choose to leave.
The above are only possible reasons, and the specific reasons may vary according to individual circumstances.