用Quizlet學習並牢記包含Primary Economic Activities、Secondary Economic Activities、Tertiary Economic Activites等詞語及更多內容的單詞卡。
用Quizlet學習並牢記包含Replacement rate, the number of births needed to keep a population at a stable level without immigration, requires a total fertility of、The number of European countries at or above replacement level is:、Countries with aging popul