He is an expert in musicology.

He is an expert in orthoepy, teaching pronunciation.

This room is covered with soundproofing material, so the sound doesn't leak outside.

He honked the car horn to get my attention.

An intercontinental ballistic missile is a weapon with a very large destructive power.

The launch of intercontinental ballistic missiles has become an international issue.

The intertransversarius muscle is an important part of our body, especially part of the back muscles.

I plan to travel to the Czech Republic next year.

My friend came from the Republic of the Congo.

My dream is to visit the Republic of South Africa.