I saw a flying object in the sky.

This book is written in Roman type.

The complement system of the immune system plays an important role in eliminating foreign substances in the body.

His form is just like a dancer.

His hippocampus is maintaining a healthy condition.

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?