2771. What characters can be added here so that each character contains a part of the previous character? a) 切 -> _ -> _ -> 幸 b) 妙 -> _ -> _ -> 吹

a) 切 -> 召 -> 吐 -> 幸  

切  SETSU, ki(ru), ki(reru) - cut

召  SHOU, me(su) - summon, wear, take

吐  TOU, ha(ku) - spew, vomit, give vent to

幸  KOU, shiawa(se), sachi - happiness, good fortune

b) 妙 -> 劣 -> 加 -> 吹  

妙  MYOU - strange, odd, adroit, mystery

劣  RETSU, oto(ru) - be inferior

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

吹  SUI, fu(ku) - blow