He must stop the act of polluting the river.

He lives a life that is considerate of the environment, without defiling the beautiful nature.

This mud is very deep.

This mud is deep enough to dirty the shoes.

This marshland has been known as a habitat for birds since ancient times.

My new shoes are very comfortable.

His eyes are a deep blue.

He bought new shoes.

This lake is very deep.

His eyes were filled with deep sorrow.