2324. What characters can be added here so that each character contains a part of the previous character? a) 努 -> _ -> _ -> 賜 b) 暦 -> _ -> _ -> 嘱

a) 努 -> 加 -> 員 -> 賜  

努  DO, tsuto(meru) - exert self, make efforts, strive

加  KA, kuwa(eru), kuwa(waru) - add, append, join, take part

員  IN - member

賜  SHI, tamawa(ru) - grant, bestow, confer

b) 暦 -> 早 -> 古 -> 嘱  

暦  REKI, koyomi - history

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

古  KO, furu(i) - old

嘱  SHOKU - request, entrust, commission