He is lobbying to influence politicians.

He is known as an activist for environmental issues.

He is a very active person.

He is active as a member of that external body.

Action potential is an important mechanism for nerve cells to transmit information.

He is actively participating in social movements.

He is passionately engaged in extracurricular activities.

Every weekend, I do volunteer work at a local shelter.

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

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