Matched context for preclude and prevent back

The page lists matched contexts for preclude and prevent back.

Share - preclude	Share - prevent back	Phrase
8.35%	22.16%	{preclude or prevent back} flow [perform operation]
1.77%	16.84%	valve [does] {preclude or prevent back}
1.26%	7.78%	{preclude or prevent back} fuel [perform operation]
1.58%	4.86%	substantially [degree] {preclude or prevent back}