2633. What characters can be added here so that each character contains a part of the previous character? a) 炎 -> _ -> _ -> 胆 b) 早 -> _ -> _ -> 賄

a) 炎 -> 畑 -> 胃 -> 胆  

炎  EN, honou - flame

畑  hatake - cultivated field

胃  I - stomach

胆  TAN - gallbladder, courage

b) 早 -> 古 -> 員 -> 賄  

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

古  KO, furu(i) - old

員  IN - member

賄  WAI, makana(u) - provide board, supply, furnish