The nature of the hypothesized relationship is that there might exist a PM concentration level below which further reductions no longer yield premature mortality reduction benefits.
The PM concentration level might be reduced without lowering mortality rates.
The PM concentration level might be reduced without raising  mortality rates.
The majority of what I use is oil.
A runner raises his hand in triumph as he near the finish.
the carnival had games
Nothing is running
She has no comical tics and never attempts humor.
1 man is asleep in his boat.