power off preserving {TAIL ~ means} for powering off the system after transferring the data held in the first storing means to {HEAD ~ the hard disk} 
power off preserving { TAIL ~ means } for powering off the system after transferring the data held in the first storing means to { HEAD ~ the hard disk }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD