This is our main goal.

He played a central role in the project.

Earthquakes are caused by the movement of the crust.

This area is known for producing a variety of minerals.

He ate one apple.

Is it possible to change the configuration of this computer?

It took him a year to compose that song.

Feldspar is one of the main minerals that make up the earth's crust.

The movement of tectonic plates can cause earthquakes.

Mineral oil is often used in the manufacture of cosmetics and pharmaceuticals.