{HEAD ~ The speed} of propagation is predetermined by {TAIL ~ the inherent characteristics} of the wave and the medium chosen 
{ HEAD ~ The speed } of propagation is predetermined by { TAIL ~ the inherent characteristics } of the wave and the medium chosen
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH