This grammar rule is using the exclusive form.

Exclusive form of grammar is used to refer to a specific object only.

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

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

The characteristic of annelids is that their bodies are divided into ring-shaped segments.

This butterfly valve is used to control the flow of fluid.

He explained in detail about the structure of the sphenoid bone.

She is learning the grammar of the present progressive form.

This shape is a parallelogram.

This shape is a parallelogram.