Sufficient caution is necessary when handling radioactive materials.

It is reported that North Korea has conducted another underground nuclear test.

He is an expert in experimental psychology.

He is spending a lot of time on experimental research.

Cerebrospinal fluid plays an important role in protecting the brain and spinal cord.

I use mouthwash every day after brushing my teeth.

In this forest, various organisms live by building a relationship of mutualism.

In ancient Japan, the Housou clan played an important role.

The phrase 'the good and bad deed cancel out' perfectly describes his past actions.

Ainoya-san is my best friend.