The source of this river is at the top of the mountain.

The geology of this area is mainly composed of aqueous rocks.

We went to the aquarium with our family on the weekend.

Her heart is pure, with no malice at all.

This lake is filled with fresh water.

I'm planning to buy a new desktop computer.

He called that country the axis of evil.

Our house and his house are separated by a narrow body of water.

Numerical analysis is a branch of mathematics that studies techniques and theories for solving mathematical problems numerically.

We must not forget the horror of nuclear and hydrogen bombs.