the survival of the fittest

an organism; a life form

(rare) duality

the general trend or situation, the zeitgeist, the current of the times / a major authority, influence, or power / (business, stocks) a major swing or trend in prices lasting at least half the year

clear stream

holy, sacred

holiness, sacredness, sanctity

pupil, educatee, student (especially in junior high schools (中学校) or high schools (高校) in Japan)

calm, composed

the act of manufacturing or producing something carefully or specially; the act of making something of a special shape or quality / something so made