He participated in the anti-war movement.

He is participating in the anti-war movement.

The air in this area is greatly affected by pollutants emitted from factories.

The existence of dark matter has not yet been fully proven.

Antibiotics don't work for colds, so please don't take them unnecessarily.

We exist as a part of the material world.

This food may contain carcinogens.

In physics, when a particle and an antiparticle come into contact, annihilation occurs.

In physics, it is said that when matter and antimatter come into contact, they undergo annihilation.

The opposite angles of a quadrangle intersect each other.