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