He is doing special exercises to strengthen his spinalis muscle.

It looked like he had a bony spine on his back.

The mobile phone communication is unstable because the base station in this area is broken.

This obsolete song was once very popular, but it is no longer performed today.

He is a complete outsider to this issue.

He is facing a difficult situation.

His opinion is the polar opposite of mine.

You can solve this problem using polar coordinates.

In this experiment, we will use various inorganic compounds.

He showed the whites of his eyes in surprise.