Combining {HEAD ~ a CO2 cleaning step} with {TAIL ~ HF treatment} is unique in that CO2 cleaning has traditionally been used only after a used workpiece underwent mechanical stripping which produced debris particles 
with
Combining { HEAD ~ a CO2 cleaning step } with { TAIL ~ HF treatment } is unique in that CO2 cleaning has traditionally been used only after a used workpiece underwent mechanical stripping which produced debris particles
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH