That theory is unscientific and has no evidence at all.

He is an expert in astrophysics.

He is majoring in belles-lettres.

She is majoring in clinical psychology.

He lost his sense of direction.

Demography is a part of social science that studies the structure, evolution, and problems of human population.

He is studying hard to enter the next level of school.

My younger brother will enter the faculty of law next year.

He commutes to school by bicycle every day.

He decided to drop out of school due to the difficulty of his studies.