I used the student discount at the movie theater.

They were trading goods through barter.

We exchanged our old books for new ones through barter.

The educational system in Japan consists of six years of elementary school, three years of junior high school, three years of high school, and four years of university.

He is an excellent student.

I am majoring in embryology at university.

He is an excellent medical student.

Sexology is the scientific study of human sexual behavior and sexuality.

The sexology class is very interesting.

He is an expert in biochemistry.