2303. What characters can be added here so that each character contains a part of the previous character? a) 柔 -> _ -> _ -> 眠 b) 哲 -> _ -> _ -> 黒

a) 柔 -> 林 -> 相 -> 眠  

柔  JUU, NYUU, yawa(rakai) - soft

林  RIN, hayashi - woods

相  SOU, SHOU, ai - aspect, minister, partner

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

b) 哲 -> 吐 -> 埋 -> 黒  

哲  TETSU - wisdom

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

埋  MAI, u(maru), u(meru), u(moreru) - bury, be buried, filled up

黒  The "Kuro" radical - black