Matched context for penetration and expulsion

The page lists matched contexts for penetration and expulsion.

Share - penetration	Share - expulsion	Phrase
4.11%	16.16%	fuel {penetration or expulsion}
3.13%	13.56%	prevent {penetration or expulsion} [perform operation]
0.84%	9.03%	gas {penetration or expulsion}
0.92%	7.09%	permit {penetration or expulsion} [perform operation]
0.76%	4.04%	reduce {penetration or expulsion} [perform operation]
0.56%	3.43%	air {penetration or expulsion}