A smarter woman would have had an extra set of keys.

She came out with her extra set of keys, stopped and stared at the car.

An extra set of photographs, for God's sake, left behind where anyone could find them.

"And I'm going to use it as an extra set of eyes."

Each aircraft will be acting as an extra set of eyes for the other in an attempt to see before being seen.

It was true an extra set of hands would be good right now.

You can see for yourself that I could really use an extra set of hands.

You know, lady comes in, wants an extra set for the maid?

Or to serve as an extra set of eyes and ears?

He simply wants an extra set of eyes to watch his back.