2066. What characters can be added here so that each character contains a part of the previous character? a) 姿 -> _ -> _ -> 幸 b) 普 -> _ -> _ -> 鳴

a) 姿 -> 如 -> 吐 -> 幸  

姿  SHI, sugata - figure, form, shape, appearance

如  JO, NYO - equal, like, as, as if

吐  TOU, ha(ku) - spew, vomit, give vent to

幸  KOU, shiawa(se), sachi - happiness, good fortune

b) 普 -> 早 -> 古 -> 鳴  

普  FU - general, universal

早  SOU, SA, haya(i) , haya(meru) - early, fast, hasten

古  KO, furu(i) - old

鳴  MEI, na(ku), na(ru)(rasu) - cry, sing, howl, ring