A secondary subsidiary is generally a secondary subsidiary of the head office or a branch established in other cities. Second-level companies generally provide services for superior companies, or are full-time companies in a professional field of superior companies.
Because the subsidiary holds more shares and occupies a dominant position, it is upgraded from the second level to the first level.
If a company owns more than 50% of the shares of another company, it is bound to be able to control the company.