The Asuka Period is a part of Japanese history, a time when culture and arts greatly developed.

The Muromachi period is a part of Japanese history, a time when many cultural changes occurred.

The Kamakura period was a very important time in Japanese history.

The Sengoku period is a part of Japanese history.

She is learning the grammar of the present progressive form.

The Neolithic was an important period in human history.

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

The Bronze Age was an important period in human history.

The Paleolithic is the first era of human history.

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