This world where people live is beautiful, and sometimes harsh.

This old document details the lifestyle of humans.

My biological clock is completely messed up.

Overdose may have a negative impact on health.

His phone rang while he was in the middle of a meal.

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.

He is involved in the development of androids.