C：我主修经济学。

C: My major is economics.

youdao

我主修经济学，副课是法语。

My major subject is Economics and my minor subject is French.

youdao

我想在大学里主修经济学。

I intend to major in economics in college.

youdao

经济学是他的主修课。

Economics is his major.

youdao

经济学是我的主修课程。

Economics is my major.

youdao

经济学是我的主修课程。

Economics is my major.

youdao