Preferred for {TAIL ~ the heteropolyacid} is at least one type selected from among {HEAD ~ silicomolybdic acid}, phosphorotungstic acid, silicotungstic acid, phosphoromolybdic acid and silicotungstomolybdic acid 
Preferred for { TAIL ~ the heteropolyacid } is at least one type selected from among { HEAD ~ silicomolybdic acid } , phosphorotungstic acid , silicotungstic acid , phosphoromolybdic acid and silicotungstomolybdic acid
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH