The liquid reagent 17 is then squirted directly onto {HEAD ~ the portion} of the test pad 12 bearing {TAIL ~ the first reagent} 13 
The liquid reagent 17 is then squirted directly onto { HEAD ~ the portion } of the test pad 12 bearing { TAIL ~ the first reagent } 13
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH