684. What character can be added to both of these characters to give other characters? 士_ -> _属

Answer:

士  SHI - samurai, man, scholar

属  ZOKU - belong to

Add 口:士+口 口+属 

口  KOU, kuchi - mouth

吉  KICHI, KITSU, yoshi - good luck

嘱  SHOKU - request, entrust, commission