{TAIL ~ Each} of {HEAD ~ the casings} includes a coverable opening through which the electrolyte solution within the cell is replaceable 
{ TAIL ~ Each } of { HEAD ~ the casings } includes a coverable opening through which the electrolyte solution within the cell is replaceable
TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH