2044. What characters can be added here so that each character contains a part of the previous character? a) 畑 -> _ -> _ -> 思 b) 切 -> _ -> _ -> 珠

a) 畑 -> 累 -> 細 -> 思  

畑  hatake - cultivated field

累  RUI - involvement, trouble, accumulation

細  SAI, hoso(i), hoso(ru), koma(kai) - thin, narrow, slender

思  SHI, omo(u) - think, believe

b) 切 -> 召 -> 呈 -> 珠  

切  SETSU, ki(ru), ki(reru) - cut

召  SHOU, me(su) - summon, wear, take

呈  TEI - offer, present, exhibit

珠  SHU - pearl