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.

This food may contain carcinogens.

He dreams of entering the world of entertainment.

He is successful in the business world.

He is highly respected in the education world.

He is deeply interested in the spiritual world.

In biology, a subkingdom is one of the large units in taxonomy.

The animal kingdom is incredibly diverse, and it is said that there are still species that have not been discovered.

The animal kingdom is known for its diversity and complexity.