Matched context for intrusion and backflow

The page lists matched contexts for intrusion and backflow.

Share - intrusion	Share - backflow	Phrase
20.43%	22.00%	prevent {intrusion or backflow} [perform operation]
2.97%	4.28%	gas {intrusion or backflow}
8.66%	1.33%	water {intrusion or backflow}
2.64%	1.08%	air {intrusion or backflow}