2273. What characters can be added here so that each character contains a part of the previous character? a) 普 -> _ -> _ -> 嘱 b) 誓 -> _ -> _ -> 餓

a) 普 -> 早 -> 古 -> 嘱  

普  FU - general, universal

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

古  KO, furu(i) - old

嘱  SHOKU - request, entrust, commission

b) 誓 -> 詳 -> 養 -> 餓  

誓  SEI, chika(u) - swear, pledge, vow

詳  SHOU, kuwa(shii) - detailed, full, familiar with

養  YOU, yashina(u) - rear, support, adopt

餓  GA - starve