根据语境，在题后括号中选出恰当词语填空。(4分)

曾经有这样一个瑰丽多姿的地方，那里有大雪纷飞的北国风光，有

A．的戈壁奇观，有

B．的江南小镇，有瘴气袭人的荒蛮丛林，有

C．的友情，有凄恻缠绵的爱情，有宦游的漂泊零落，有归家的

D．这，就是唐诗。(温暖湿润肝胆相照喜悦温馨黄沙烈日)A                B               C                D          

A private agreement between two parties to exchange a series of future cash flows, with at least one of the two series of cash flows determined by a later outcome, is best characterized as a (n) :

A．

B．

C．