{HEAD ~ The streams} can, more or less, contain {TAIL ~ equal parts} of each component and are used without further processing or purification 
contain
{ HEAD ~ The streams } can , more or less , contain { TAIL ~ equal parts } of each component and are used without further processing or purification
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH