I lost my precious belongings.

Feudalism characterized the social system of medieval Europe.

Changes in the social system inevitably occur with time.

Slavery is something that robs human dignity and is absolutely unacceptable.

Do you understand the necessity of this project?

That information is unnecessary.

That information is completely unnecessary.

He thinks that war is a necessary evil.

I didn't think he would come.

When I hear that song, old memories come to mind.