It's a mixture that doesn't let you sleep well and cuts into concentration.

"I go into deep concentration before a race," he explained.

Fleet safe but unable to do much except fire shells into concentration they see to form.

"You seem fascinated, Pete," Cyberal said in the sort of voice one used to break into intense concentration.

Suddenly he was shocked into full concentration, as if he were flying a combat mission.

And then Haskins does an amazing thing: he simply wills himself into total concentration.

It was as if she were drawing energy from the air around them, while Paris's own faded into labored breathing and concentration.

The play became more intense as conversation lapsed into concentration.

I don't like to break into such concentration, F'lessan replied.

"Lieutenant," a voice called out, breaking into concentration, "we've got 'em all turned on now."