This grammar rule is using the exclusive form.

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

He understands the meaning of the proverb 'Teaching is half learning', which means that teaching leads to one's own learning.

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

He always keeps in mind the phrase 'If one learns without thinking, it is a waste.'

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

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

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

He drew a straight line using a T-square.

She is learning the grammar of the present progressive form.