He was half dead from fatigue.

His actions change depending on the circumstances.

Kuni was fascinated by the story in the picture book.

Mr. Kusanagi is my best friend.

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.