Riemannian geometry is a field of mathematics that studies geometric objects such as curves and surfaces.

He is an expert in applied physics.

He is an expert in physical anthropology.

He is an expert in physical anthropology, conducting research on human evolution.

Gestalt psychology is an important means to understand human cognitive processes.

He is very interested in ecology.

The ecosystem of this lake is very fragile.

He ate one apple.

It is important for each person to fulfill their role.

He has a very passive personality.