That theory is unscientific and has no evidence at all.

He is an expert in computer science.

The Ministry of Education is responsible for Japan's educational policy.

My father is an expert in otolaryngology.

The history of the Empire of Japan is very interesting.

The police contacted the victim's family.

He is an excellent translator.

The users of this website are increasing every day.

He is a famous composer.

He is a very talented arranger.