1570. What characters can be added here so that each character contains a part of the previous character? a) 炎 -> _ -> _ -> b) 知 -> _ -> _ -> 黒

Answer:

a) 炎 -> 畑 -> 累 -> 約

炎  EN, honou - flame

畑  hatake - cultivated field

累  RUI - involvement, trouble, accumulation

約  YAKU - approximately, promise

b) 知 -> 吐 -> 埋 -> 黒

知  CHI, shi(ru) - know

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