{HEAD ~ Cross arm} 10, however, is filled with metal, or it is a hollow metal section which is preferably filled with {TAIL ~ a compound} 
{ HEAD ~ Cross arm } 10 , however , is filled with metal , or it is a hollow metal section which is preferably filled with { TAIL ~ a compound }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL