Why is China Railway Shanghai Bureau so short of people?

The reason for the shortage of personnel in China Railway Shanghai Bureau is that there are many people leaving the company. Inquiring about the personnel information of China Railway Shanghai Bureau shows that China Railway Shanghai Bureau is recruiting a large number of employees due to the large number of employees leaving the company. There are many people leaving the company, so China Railway Shanghai Bureau is short of people. The reason for the large number of resignations from China Railway Shanghai Bureau is that fresh graduates do not have the right majors at China Railway Shanghai Bureau and are unable to withstand the work pressure of China Railway Shanghai Bureau.