The relative decline of the United States in the share of world output and world exports reflects _____. 美国在世界产出和出口中所占份额的相对下降反映了美国经济的衰退。
A.
an increase in the barriers to foreign trade in the U.S.美国对外贸易壁垒的增加
B.
the deepening of the global financial crisis全球金融危机不断深化
C.
the reduced industrialization in developing nations发展中国家工业化程度的降低
D.
the growth in the economic development of the world economy世界经济发展的增长