What do the girls in China Railway Third Bureau usually do?

The recruitment project of China Railway Third Bureau includes the profession of clerk. As can be seen from the recruitment information, the monthly salary of clerks is around 4000 yuan. Generally speaking, most employees are girls.

China Railway Third Bureau generally refers to China Railway Third Bureau Group Co., Ltd. (formerly the Third Engineering Bureau of the Ministry of Railways), which is a large-scale construction enterprise with comprehensive construction capacity and a wholly-owned subsidiary of China Railway Corporation, one of the world's top 500 companies.