2242. What characters can be added here so that each character contains a part of the previous character? a) 架 -> _ -> _ -> 結 b) 篤 -> _ -> _ -> 紳

a) 架 -> 柱 -> 素 -> 結  

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

柱  CHUU, hashira - pillar, column, pole

素  SO, SU - element, naked, simple

結  KETSU, musu(bu), yu(u) - tie up, bind

b) 篤 -> 駐 -> 素 -> 紳  

篤  TOKU - serious, cordial

駐  CHUU - stop, reside

素  SO, SU - element, naked, simple

紳  SHIN - gentleman