{HEAD ~ A pair} of blowers 83, 83, blow {TAIL ~ cooling air} over heat sinks 82, 82 
blow
{ HEAD ~ A pair } of blowers 83 , 83 , blow { TAIL ~ cooling air } over heat sinks 82 , 82
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH