She had a cool and sharp brain for business, did Darcy.

But behind the football hooligan face lay a sharp, analytical brain.

And suddenly he was alert, his brain sharp and focused.

Lily sat on at the table, her sharp foolish little brain working things out.

He possessed a sharp, intelligent brain, and he was using it in this.

A true gambler has to have a sharp brain.

Knowing of a risk can also be an incentive for working to keep a sharp brain.

Fragments of memory shot through my brain, sharp as shrapnel.