2105. What characters can be added here so that each character contains a part of the previous character? a) 化 -> _ -> _ -> 胞 b) 響 -> _ -> _ -> 嘱

a) 化 -> 旨 -> 明 -> 胞  

化  KA, KE, ba(keru) - transform

旨  SHI, mune - purport, content, instruction

明  MEI, MYOU, aka(rui), a(keru) - bright

胞  HOU - sac, sheath, placenta

b) 響 -> 章 -> 古 -> 嘱  

響  KYOU, hibi(ku) - sound, resound, affect, echo

章  SHOU - chapter, badge, mark

古  KO, furu(i) - old

嘱  SHOKU - request, entrust, commission