The secret to longevity is having healthy internal organs.

This castle was constructed in the 16th century.

He is planning to construct a new house.

This shape is called a gyrobifastigium.

He apologized to me sincerely.

They became in a relationship of mutual love.

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.

He drew a straight line using a T-square.