Matched context for air-intake and non-return

The page lists matched contexts for air-intake and non-return.

Share - air-intake	Share - non-return	Phrase
15.42%	83.96%	{air-intake or non-return} valve
2.50%	2.63%	{air-intake or non-return} opening
2.20%	0.71%	{air-intake or non-return} system