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