The Proterozoic eon is the longest era in the history of the Earth.

This is the most beautiful flower.

The Proterozoic eon is the longest era in the history of the Earth.

The Eoarchean eon is the oldest era in the history of the Earth.

The Neoproterozoic era was a very important period in the history of the Earth.

Living in this age is very exciting.

His hair is very long.

He is interested in history.

The Archaean eon is the oldest era in the history of the Earth.

His wedding was truly magnificent.