My keys are inside the house.

He is quite a good cook.

I think his Japanese has improved quite a bit, hasn't it?

I am busy with work during the daytime.

The Neoarchean eon was a very important period in the history of the Earth.

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

The Paleoarchean eon is a very old era in the history of the Earth.

I want to go to Mongolia.

I am an Earthling.

We are searching for extraterrestrial life.