Matched context for prevent back and preclude

The page lists matched contexts for prevent back and preclude.

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