They are my best friends.

I prefer to use natural cosmetics.

I am interested in the ancient Kyūjitai form of 雅楽.

He is an expert in ecology.

He is majoring in medicine.

In this experiment, you can observe a chemical reaction.

This substance undergoes a chemical change when heat is applied.

He is an expert in somatology, with a deep knowledge of the functions of the human body.

He stated his opinion outspokenly as '咢'.

He is majoring in psychology.