675. What characters can be added here so that each character contains a part of the previous character? 針 -> _ -> _ -> 幸

Answer:

針  SHIN, hari - needle

幸  KOU, shiawa(se), sachi - happiness, good fortune

針 -> 古 -> 吐 -> 幸

古  KO, furu(i) - old

吐  TOU, ha(ku) - spew, vomit, give vent to