As mentioned above, {HEAD ~ the resistance} varies with {TAIL ~ flow}, but it does not vary significantly with pressure 
varies with
As mentioned above , { HEAD ~ the resistance } varies with { TAIL ~ flow } , but it does not vary significantly with pressure
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH