Doors or gates are provided to control the amount and {HEAD ~ width} of the discharge of {TAIL ~ particulate material} to the highway surface 
Doors or gates are provided to control the amount and { HEAD ~ width } of the discharge of { TAIL ~ particulate material } to the highway surface
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH