Matched context for back-flow and shortage

The page lists matched contexts for back-flow and shortage.

Share - back-flow	Share - shortage	Phrase
7.24%	18.47%	oil {back-flow or shortage}
27.51%	4.77%	prevent {back-flow or shortage} [perform operation]
6.55%	16.30%	fuel {back-flow or shortage}
9.86%	7.80%	fluid {back-flow or shortage}
4.08%	4.84%	air {back-flow or shortage}