What can we learn from paragraph 3?A、The government tends to dominate the market.
B、The manufacturers ignore the consumers' demands.
C、The businessmen take over the American economy completely.
D、The consumers' decisions take the key role in the American economy.
【正确答案】：D
【题目解析】：推理判断题。题干要求根据第三段内容做出正确的推理。上文第二段提到国家商业机器的表现取决于千万消费者。第三段接着说到the heart of free market system是人们的各种决策，而企业和政府都根据消费者的喜好制订计划（Business and government take their cues from consumers, changing plans to meet their wants and needs），可见消费者在美国经济中起到关键作用，D选项符合文章原意。此外还可以采取排除法。因为选项A、B、C的内容都与本段内容冲突，所以可以排除。故而正确答案是D。