2187. What characters can be added here so that each character contains a part of the previous character? a) 畑 -> _ -> _ -> 放 b) 炎 -> _ -> _ -> 堀

a) 畑 -> 累 -> 紡 -> 放  

畑  hatake - cultivated field

累  RUI - involvement, trouble, accumulation

紡  BOU, tsumu(gu) - spin, make yarn

放  HOU, hana(reru), hana(tsu), hana(su) - to let loose, release, emit

b) 炎 -> 畑 -> 里 -> 堀  

炎  EN, honou - flame

畑  hatake - cultivated field

里  RI, sato - village

堀  hori - moat, canal, ditch