His grandfather was an officer in the Japanese Army.

The Edo oil shark is a type of shark that lives in the deep sea.

The Indo-European languages are some of the most widely spoken in the world.

The Paleolithic is the first era of human history.

The Bronze Age was an important period in human history.

The Neolithic was an important period in human history.

The Mesolithic is the era between the Paleolithic and the Neolithic.

The Azuchi-Momoyama period, also known as the Oda-Nobunaga period, was a very important time in Japanese history.

The Azuchi-Momoyama period was a very important time in Japanese history.

He is studying late into the night to learn a new computer language.