He is interested in diachronic linguistics studies.

He is interested in synchronic linguistics.

He is thought to be a very unsociable person.

She started a special exercise to strengthen the incisivus labii inferioris muscle.

General relativity is a theory of physics proposed by Einstein.

Special relativity is one of the fundamental theories of physics.

This area is seriously contaminated with radioactive isotopes.

He feels dizzy when he stands up suddenly due to orthostatic hypotension.

My father was diagnosed with ankylosing spondylitis.

In organic chemistry, pyruvic acid plays an important role.