substitution

n.代替

subsidize, subsidise, subsidy, subsist, subsistence, subsistence crop, subsistence level, subsoil, subsonic, substance, substandard, substantial, substantially, substantiate, substantiation, substantive, substantively, substation, substitute, substitute for, substitute...for, substratum, substructure, subsume, subtenancy, subtenant, subtend, subterfuge, subterranean, subtitle, subtle, subtlety, subtly, subtopia, subtopic, subtotal, subtract, subtraction, subtropical, suburb, suburban,