He kept digging to explore the secrets of the underground.

A trial was held at the small district court.

In this lake, denitrification is actively taking place.

This soil is active in denitrification, releasing nitrogen into the atmosphere.

Sohachi is my best friend.

Shoyo is my best friend.

Sho is my best friend.

Kiyoshi is my best friend.

I live in Chiba Prefecture.

Saburo is my best friend.