The Neogene period is a part of the geological era, which lasted from about 23 million years ago to about 2.6 million years ago.

The Paleogene period was a very important time in the history of the Earth.

The Quaternary is the most recent era in Earth's history.

He is said to have a sharp sixth sense.

On the seventh day of creation, God finished all his work and rested.

The First International was an international organization of workers.

The Second International was established to protect the rights of workers.

He is learning how to use the second adjective.

His first adjective is 'beautiful'.

I have been studying Japanese for three months.