According to another object of the invention, {HEAD ~ the middle member} comprises a sandwich of wire trusses and {TAIL ~ polystyrene materials} 
comprises
According to another object of the invention , { HEAD ~ the middle member } comprises a sandwich of wire trusses and { TAIL ~ polystyrene materials }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL