He has been working as a doctor in this town for many years.

I haven't seen him for a long time.

He has been working as a doctor in this town for many years.

Un is my best friend.

This room is piled up with things like the character '蘊'.

This area is rich in natural abundance.

This knowledge has been accumulated over many years.

I'm always amazed by his extensive knowledge.

What is the volume of this box?

This math problem requires finding the product.