nitrogen cycle

(informal) I know, right!?

the four gods 青龍(せいりょう) (Seiryō), 朱雀(すざく) (Suzaku), 白虎(びゃっこ) (Byakko), 玄武(げんぶ) (Genbu), imported to Japan from Chinese mythology

銃剣: (military, weaponry) bayonet