Thereafter, a quantity of primer material is positioned within the tubing through {TAIL ~ the second, open end} thereof and deposited on {HEAD ~ an internal bottom surface} of the tubing 
Thereafter , a quantity of primer material is positioned within the tubing through { TAIL ~ the second , open end } thereof and deposited on { HEAD ~ an internal bottom surface } of the tubing
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH