{HEAD ~ This insertion opening} can be advantageously closed by {TAIL ~ means} of a drawstring or a rain protection flap 
advantageously closed by
{ HEAD ~ This insertion opening } can be advantageously closed by { TAIL ~ means } of a drawstring or a rain protection flap
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH