He devoted his life to the study of something.

He is studying at the library every day.

He is majoring in agronomy.

He is majoring in criminology at university.

When he was a schoolchild, he used to go to the library every day and read books.

I am majoring in anthropology at university.

He has a wide range of knowledge.

He is known as a person of erudition.

He is an expert in pathology.

Demography is a branch of social science that studies the structure, distribution, and changes in human population.