You must be able to concentrate your mind on one object for five minutes.

I could not concentrate my mind upon the papers in front of me.

There was one way he knew to concentrate his mind for the solution of a problem.

How can a man concentrate his mind with all this noise?

Personal liability, in other words, can concentrate a director's mind.

Now look again; choose a single image, and concentrate your mind on that.

He tried to concentrate his mind on some one definite thing.

He turned away from the forest and sought to concentrate his mind upon other things.

This will concentrate their minds and make sure they do what is right.

Then he concentrated his mind on the images coming from the eye that was watching the officers of the court.