Demography is an important tool for understanding various aspects of society.

He is an expert in astrophysics, and his research is highly valued around the world.

I studied linear algebra at university.

Palaeoclimatology is the science that studies the past climate of the Earth.

He is an expert in paleobotany.

He is an expert in paleozoology and has a deep knowledge about the ecology of dinosaurs.

Paleoecology is a field of study that investigates the relationship between past organisms and their environment.

Paleogeography is a study that researches the past geographical conditions of the Earth.

He is an expert in orthoepy, teaching pronunciation.

I am learning the basic concepts of differential geometry.