Then, {HEAD ~ the system} reads {TAIL ~ data} in a plurality of sectors of the disk drive and saves the data to the free memory space with a reading routine 
reads
Then , { HEAD ~ the system } reads { TAIL ~ data } in a plurality of sectors of the disk drive and saves the data to the free memory space with a reading routine
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH