Shasa knew that expression so well, when his mother indulged in furious concentration.

He spiced and seasoned and bit his tongue in furious concentration.

With furious concentration he sent for books, instruments, chemicals, all manner of tools and equipment.

Irene's eyes bent in furious concentration upon the grass, "With whom.

Instead she kept pacing, her face a study in furious concentration.

With $50,000 at stake, there was furious concentration and considerable tension.

The witchlet stared at it, brow puckering in furious concentration.

"Oh," Cooper said, and his forehead knit in a moment or two of furious concentration.

All eyes bent in furious concentration on the board.

He listened without saying a word, driving all the time with a furious concentration, his foot hard down on the accelerator.