It's difficult to understand his explanation.

He is deeply influenced by the teachings of Buddhism.

He deeply believes in Buddhism.

It's difficult to understand his explanation.

The cause of his lateness was the train delay.

The cause of his lateness was the train delay.

Mr. In deeply understands the teachings of Buddhism.

Smoking is considered a cause of carcinogenesis.

His eyes are a deep blue.

This lake is very deep.