The external urethral sphincter is an important muscle for controlling the excretion of urine.

The internal urethral sphincter plays a crucial role in controlling the flow of urine.

In this chemical reaction, a specific isotope is produced.

She wrote her name in cursive script.

This sentence is written in bold typeface.

This pathogen is very dangerous to humans.

There is a possibility that unknown lifeforms exist on this planet.

He is deeply researching the theory of real number fields.

He saw the light through the transparent object.

This colony is forming a unique ecosystem.