He is drawing a picture using boneblack.

Ossification is a biological process that refers to the transformation of tissue into bone.

He receives confession at the church every week.

He went to the church to confess his sins.

Maintaining national sovereignty is our top priority.

In the severe cold, he went to work every day.

He should change his stubborn and narrow-minded way of thinking.

His stubbornness and narrow-mindedness make it difficult to accept new ideas.

My dream is to own a Corvette someday.

My friend works at a call center.