You need a washer to secure this bolt.

The voltage of this battery is 1.5 volts.

A special bolt is needed to repair this machine.

Your cooperation is needed for this project.

I need you.

I fixed the bicycle tire.

The fixation of this chair is not firm.

An electron volt is a unit of energy.

In this experiment, energy is measured in electron volts.

He thinks that war is a necessary evil.