Might not be the best proving ground.

The working model's at the proving ground in Palmdale.

Division was one of our best proving grounds.

Israel and Palestine should not be a proving ground for intellectual preferences or political games.

We've been using your store as a proving ground for prospective Intersect candidates.

We've been using your store as a proving ground... ...for prospective Intersect candidates.

The scouting Combine -- the annual proving ground for college seniors who dream of becoming pro players...

But the proving grounds' importance stems far beyond it's strategic geographic value.

Those in favor of removing the aberdeen proving ground from the list of closures?

But the Proving Ground's importance stems far beyond its strategic geographic value.