Ordinarily, mineral lubricating oils are used by {HEAD ~ reason} of their availability, {TAIL ~ general excellence}, and low cost 
of
Ordinarily , mineral lubricating oils are used by { HEAD ~ reason } of their availability , { TAIL ~ general excellence } , and low cost
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH