The Chinese_____fifty-six nationalities,each of whom has their own characteristic.    [ ]

A. is consisted of    

B. consists in    

C. is made of    

D. consists of

某商品价格下降了20%，供给数量下降了40%，需求数量增加了60%，计算该商品的供给价格弹性和需求价格弹性。