The very low oil prices of the 1990s helped to keep down running costs.

I can't say anything more without getting into the stuff that we have to keep down.

They can do greater things than the people who keep them down.

It was the only thing she had been able to keep down all day.

Shouldn't I stop trying to do some science and keep my head down?

Then keep down until the day watch comes, if any.

He had to use both hands to keep her down.

He had not been able to keep any food down all day.

How will he be able to keep his head down?

Yes, I mean this would help to keep it down.