He is a professor of algebra.

He is majoring in law at university.

He is majoring in engineering.

I am majoring in biology at university.

He proposed a new theory about quantum mechanics.

He is an expert in petrochemistry.

He is an expert in folklore studies, and his research is highly regarded worldwide.

The concept of chemical equivalent is essential for understanding chemical reactions.

We are growing vegetables without using chemical fertilizers.

He decided to suspend his studies for health reasons.