That is, as described previously, {HEAD ~ the diazotizing reagent} and the coupling reagent together with a necessary amount of an acid must be placed in {TAIL ~ the pores} of the porous body 
placed in
That is , as described previously , { HEAD ~ the diazotizing reagent } and the coupling reagent together with a necessary amount of an acid must be placed in { TAIL ~ the pores } of the porous body
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH