1366. What character can be added to both of these characters to give other characters? 北_ -> _包

Answer:

北  HOKU, kita - north

包  HOU, tsutsu(mu) - wrap

Add 月:北+月 月+包 月 背 胞

月  GETSU, GATSU, tsuki - moon, month

背  HAI, se, somu(ku), somu(keru) - back, height, act contrary to, avert

胞  HOU - sac, sheath, placenta