This area is seriously contaminated with radioactive isotopes.

This area is affected by radioactive fallout from past nuclear tests.

His language contains many ejective sounds.

He ate one apple.

It is important for each person to fulfill their role.

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.

It is said that antimatter has properties opposite to those of matter.

We exist as a part of the material world.