This concept was proven practical by an Australian design.

It wasn't one that was likely to prove practical in a fleet action, of course.

The new techniques might not prove practical for computer control, however, because they require multimillion-dollar machines.

So far, no method of shielding has proved both effective and practical.

A turn from the highway might be advantageous, but he doubted if it would prove practical.

This proved practical and a prototype was quickly developed.

"To a man my age, a cigar would prove much more practical."

The task is so daunting that fusion power may never prove practical.

In practice, no one is yet sure what services will prove practical and what consumers might be willing to pay for them.

A complete ban on smoking in restaurants and bars has proved not just practical, but also good for business.