1975. What characters can be added here so that each character contains a part of the previous character? a) 劣 -> _ -> _ -> 球 b) 架 -> _ -> _ -> 胞

a) 劣 -> 加 -> 呈 -> 球  

劣  RETSU, oto(ru) - be inferior

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

呈  TEI - offer, present, exhibit

球  KYUU, tama - ball, sphere

b) 架 -> 棋 -> 期 -> 胞  

架  KA, ka(keru), ka(karu) - hang, build (a bridge)

棋  KI - go, shogi, Japanese chess

期  KI, GO - time, period, term

胞  HOU - sac, sheath, placenta