He is majoring in Sinology at university.

He is an expert in bibliography and works in many libraries.

He is an expert in malacology, focusing particularly on the study of snails.

I am majoring in nutrition science at university.

He is an expert in dynamics.

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

He has a deep interest in etymology.

He is an expert in bryology and is studying many types of moss.

He is good at solving geometry problems.

He is majoring in linguistics.