He always tries to stay on the straight and narrow.

I played a quarter note on the piano.

A rational number is a number that can be expressed as a fraction.

A real number can be either a rational number or an irrational number.

She is a registered nurse at the hospital.

Please provide your registration number.

She is Rh-negative.

I enjoy swimming.

I have always wanted to visit Viet-Nam.

The political campaign turned into a war of nerves as both candidates resorted to aggressive tactics.