What is the main business of the main and auxiliary separation power enterprises? What is a secondary industry?

What is the main business of the main and auxiliary separation power enterprises? A: All work related to production is the main business; What is a secondary industry? Answer: All auxiliary posts are auxiliary businesses, such as property management companies, canteens, kindergartens, hospitals, life service companies, cinemas and so on. They are all auxiliary businesses, and some are related to production, such as installation companies, Jian 'an companies and design institutes. Anything that has nothing to do with power grid production and operation is regarded as auxiliary business.