{HEAD ~ The pulse train} fed to the base of transistor Q1 has {TAIL ~ a period} P and a duty cycle less than 50 percent 
has
{ HEAD ~ The pulse train } fed to the base of transistor Q1 has { TAIL ~ a period } P and a duty cycle less than 50 percent
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH