We exist as a part of the material world.

He is deeply interested in the spiritual world.

He is successful in the business world.

He is highly respected in the education world.

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

Learning about the history of the frontier is important for understanding our past.

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.

He likes to take a walk in the park at dusk.

We should always remember the power of Kannon in difficult times.