This rock drill is very efficient and can quickly cut through rock.

The bedrock of this area is very hard.

The compound eyes of insects are made up of many small lenses.

Many insects have simple eyes.

We had a picnic on the gulf coast.

The view of the opposite shore is very beautiful.

He has an obstinate personality and rarely changes his mind once he has made a decision.

His obstinacy is recognized by everyone.

His discernment is very sharp, he doesn't miss any details.

A surprised expression was on his face.