学校英语

I’m a PhD student in the CS program.

I’m a doctoral student in the CS program.

I’m a Master student in the CS program.

I’m a master’s student in the CS program.^[1]rjpond. . . 2017-09-01 [2023-02-20].

I’m a MSc student in the CS program.

I study for a PhD degree in CS. 注意这里不用’s。

I study for a Master’s (degree) in CS. https://ell.stackexchange.com/a/267699/65098

I read for a Master’s degree in CS.

I read for a MSc degree in CS.

I study for a Bachelor’s degree in EE.

I’m a math student.
但不能 I’m a math freshman/sophomore/junior/senior。
要说 I’m a freshman/sophomore/junior/senior in mathematics. 不能用简称math。

in: used for saying what subject someone studies.

major

She majored in History at Stanford.
She’s a French major.