substratum

n (pl substrata / 9sQb5strB:tE; ?@ 5sQbstreItE;`sQb9stretE/) 1 level lying below another 下面的一层; 底层: a substratum of rock 底层岩石. 2 (fig 比喻) foundation; basis 基础; 根基: a substratum of truth in her story 她叙述中的事实根据.

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