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