{TAIL ~ The method} also includes {HEAD ~ the step} of sensing a parameter representative of air flow through the hole 
{ TAIL ~ The method } also includes { HEAD ~ the step } of sensing a parameter representative of air flow through the hole
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH