He values his private life.

He was born as an illegitimate child and experienced many difficulties.

My grandfather used to till his privately-owned rice field.

He holds a personal grudge against me.

Using the private railway makes commuting very convenient.

Linear programming is a part of operations research and is used to find the optimal solution.

Paying the urban planning tax is a citizen's duty.

The United Nations Environment Programme is providing solutions to global environmental problems.

My younger brother is attending a middle education school.

My younger brother goes to a school for special needs.