His work is full of vigour.

The root of this tree is very deep and strong.

The roots of the plant are the source of its vitality.

Life is precious.

He is a strong person.

The source of this river is halfway up the mountain.

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

What is the source of this information?

Mr. Minamoto is my best friend.

We are looking for financial resources for the new project.