2262. What characters can be added here so that each character contains a part of the previous character? a) 架 -> _ -> _ -> 吸 b) 柔 -> _ -> _ -> 堤

a) 架 -> 杯 -> 否 -> 吸  

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

杯  HAI, sakazuki - wine cup

否  HI, ina - no, negative

吸  KYUU, su(u) - suck, inhale, smoke

b) 柔 -> 棋 -> 基 -> 堤  

柔  JUU, NYUU, yawa(rakai) - soft

棋  KI - go, shogi, Japanese chess

基  KI, moto, motoi - basis, foundation

堤  TEI, tsutsumi - bank, embankment, dike