{HEAD ~ A communication apparatus} performs {TAIL ~ specific operation} before turning off the power of the communication apparatus 
performs
{ HEAD ~ A communication apparatus } performs { TAIL ~ specific operation } before turning off the power of the communication apparatus
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH