单项选择题
A.in the developing world B.in Japan C.in Europe D.in America
A.US refusal to accept arbitration by WTO. B.US imposing tariffs on European steel. C.US refusal to pay compensation to EU. D.US refusal to lower import duties on EU products.
A.the coordination based on individual actions. B.the number of individual participants. C.the necessity of individual actions. D.the requirements for participants.