Therefore, {HEAD ~ the optical discs} of {TAIL ~ two kinds} in which the recording layers are placed at different distances can precisely be recorded or reproduced, respectively 
of
Therefore , { HEAD ~ the optical discs } of { TAIL ~ two kinds } in which the recording layers are placed at different distances can precisely be recorded or reproduced , respectively
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH