He is majoring in political science at university.

He is globally recognized as an expert in epidemiology.

I am majoring in nutrition science at university.

He used a large sum of money for investment.

He used a large amount of money for investment.

He is deeply interested in the study of Sō-Min rigaku.

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

He is majoring in psychology.

He was playing the ancient instrument, the guan.

The button of his shirt caught on a thorn.