674. What character can be added to both of these characters to give other characters? 敬_ -> _吉

Answer:

敬  KEI, uyama(u) - respect, revere

吉  KICHI, KITSU, yoshi - good luck

Add 言:敬+言 言+吉 

言  GEN, GON, i(u), koto - say, speech

警  KEI - admonish, warn

詰  KITSU, tsu(mu), tsu(meru), tsu(maru) - pack into, stuff, shorten