{HEAD ~ The method} 1 wherein {TAIL ~ the selectively controlling} includes turning off selected valve cavities 
wherein
{ HEAD ~ The method } 1 wherein { TAIL ~ the selectively controlling } includes turning off selected valve cavities
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH