He'd been an engineer for too many years to be left scratching his head, especially with an impatient captain looking over his shoulder.

At first, even the pros were left scratching their heads.

But in this case, investors are left scratching their heads.

All too often people who lose their jobs are left scratching their heads with nowhere to turn.

But parents and others have largely been left scratching their heads about who wins or loses under the plan.

Consumers looking for guidance on how long to keep products will, in most cases, be left scratching their heads.

Traders and analysts were left scratching their heads over the cause of the wild price swings.

Ordinary workers have been left scratching their heads.

Nothing could be found; no reason for the bleeding or the pain; the specialists were left scratching their heads.

At least a few other Republicans were left scratching their heads.