More preferably, {HEAD ~ the compound} having {TAIL ~ active hydrogen} is one which contains in the molecule thereof both of an acid group and a functional group having active hydrogen 
having
More preferably , { HEAD ~ the compound } having { TAIL ~ active hydrogen } is one which contains in the molecule thereof both of an acid group and a functional group having active hydrogen
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH