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

He is spending a lot of time on experimental research.

This sentence is written in bold typeface.

This pathogen is very dangerous to humans.

In this chemical reaction, a specific isotope is produced.

He is a master of martial arts.

What is this powder?

The ophthalmologist said there was something wrong with my vitreous body.

The doctor said that his vision loss was due to a problem with the vitreous body.

He is deeply researching the theory of real number fields.