{HEAD ~ The classifying openings} permit {TAIL ~ material} which is already smaller than the size of the openings to fall therethrough, thereby bypassing the comminution apparatus 
permit
{ HEAD ~ The classifying openings } permit { TAIL ~ material } which is already smaller than the size of the openings to fall therethrough , thereby bypassing the comminution apparatus
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH