The combination of the cap and connecting sections is inserted into the hollow which is provided with {HEAD ~ an opening} through {TAIL ~ its cover} 
through
The combination of the cap and connecting sections is inserted into the hollow which is provided with { HEAD ~ an opening } through { TAIL ~ its cover }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL