{TAIL ~ Reducing agent} can be conveyed back from {HEAD ~ the delivery device} to the reservoir via a return line 
{ TAIL ~ Reducing agent } can be conveyed back from { HEAD ~ the delivery device } to the reservoir via a return line
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH