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

The Bronze Age was an important period in human history.

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

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

The Neolithic was an important period in human history.

In order to keep the secret, he said, 'One word too many will be the end of me,' and didn't say anything.

The Paleolithic is the first era of human history.

He is suffering from the consequences of his own actions. It's truly a case of reaping what one sows.

He decided not to use the money obtained by illegal means, saying 'easy come, easy go.'

He believes in celibacy and says he has no intention of getting married.