Remo's mind concentrated furiously on the position of his body.

In this method of scoring the players must concentrate furiously for three days, since every overtrick is potentially significant.

He concentrated furiously, throwing up a mental block.

He concentrated furiously for a few seconds.

He concentrated furiously, tried to project himself into Trevor's brain.

Locke concentrated furiously on the tone of his next few words.

Magnus closed his eyes and concentrated furiously on the knot.

His curious work mate stiffened, then concentrated furiously on the task at hand.

Tuppence skimmed through the documents, concentrating furiously on anything that might bear a double meaning.

He bit his lips and squeezed his eyes shut, concentrating furiously.