He said nothing.

Have you decided which movie to watch?

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.

This food may contain carcinogens.

When will you go to Japan?

When are you going to Japan?