1, read one first, and then read one after graduation. This is the second major. If you all graduate, you can get two diplomas and two degree certificates (maybe one degree certificate and two diplomas are related to your major), and the treatment is basically the same as that of graduate students.

2, two at the same time, that is, a major and an assistant, this is a double degree, and when you graduate, you have a diploma and a degree certificate. And an undergraduate who graduated from a major will be treated the same in the future.