{TAIL ~ The usefulness} of {HEAD ~ the system} 100 may be greatly extended by switching to the secondary processor when battery power reaches a predetermined level 
{ TAIL ~ The usefulness } of { HEAD ~ the system } 100 may be greatly extended by switching to the secondary processor when battery power reaches a predetermined level
TAIL 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 OTH OTH OTH OTH