2907. What characters can be added here so that each character contains a part of the previous character? a) 化 -> _ -> _ -> 胆 b) 妄 -> _ -> _ -> 眠

a) 化 -> 旨 -> 明 -> 胆

化 KA, KE, ba(keru) - transform

旨 SHI, mune - purport, content, instruction

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

胆 TAN - gallbladder, courage

b) 妄 -> 妙 -> 省 -> 眠

妄 MOU, BOU - without reason, without authority

妙 MYOU - strange, odd, adroit, mystery

省 SEI, SHOU, kaerimiru, habu(ku) - ministry, reflect, omit

眠 MIN, nemu(ru), nemu(i) - sleep. sleepy, tired