He had to keep a constant check on this, key each step himself.

Nose wrinkled, she kept a constant check on the air, trying to pinpoint the slashbacks.

He kept constant check on all the mirrors, but couldn't spot anyone following them.

Thus, there is a constant check on population through war, disease, economic decline, or whatever.

I drove the first ten miles with a constant check on the rearview mirror.

With his body in the state it was he had to keep a constant check on his physiological status.

The point was that nobody was going to keep a constant check to make sure the ball really bounced back and forth.

We will have an instrument which will help us to keep a constant check on food safety in Europe.

But that would have required constant check for side effects, including possible kidney problems.

We ran constant checks on our men without their knowledge, especially those whose performance was getting shoddy.