阅读理解。 In his 1930 essay 'Economic Possibilities for Our Grandchildren ', John Keynes, a famous economist, wrote that human needs fall into two classes: absolute needs ,which are independent of what other have , and relative needs ,which make us feel superior to our fellows. He thought that although relative needs may indeed be  insatiable (无止境的) ,this is not true of absolute needs. Keynes was surely correct that only a small part of total spending is decided by the desire for superiority .He was greatly mistaken ,however ,in seeing this desire as the only source of insatiable demands Decisions to spend are also driven by ideas of quality which can influence the demand for almost all goods, including even basic goods like food. When a couple goes out for an anniversary dinner, for example ,the thought of feeling superior to others probably never comes to them. Their goal is to share a special meal that stands out from other meals. There are no obvious limits to the escalation of demands for quality. For example ,Porsche, a famous car producer, has a model which was considered perhaps the best sport car on the market. Priced at over $120,000,it handles perfectly well and has great speed acceleration. But in 2004 the producer introduced some changes which made the model slightly better in handling and acceleration. People who really care about cars find these small improvements exciting. To get them, however, they must pay almost four times the price. By placing the desire to be superior to other at the heart of his description of insatiable demands, Keynes actually reduced such demands. However, the desire for higher quality has no natural limits. 1. According to the passage, John Keynes Believed that_______. A. desire is the root of both absolute and relative needs B. absolute needs come from our sense of superiority C. relative needs alone lead to insatiable demands D. absolute needs are stronger than relative needs 2.What do we know about the couble in Paragraph 3? A. They want to show their superiority B. They find specialty important to meals C. Their demands for food are not easily satisfied. D. Their choice of dinner is related to ideas of quality. 3. What does the underlined word 'escalation' in Paragraph 4 probably mean? A. Understanding. B. Increase C. Difference D. Study 4.The author of the passage that ______. A. absolute needs have no limits B. demands for quality are not insatiable C. human desires influence ideas of quality D. relative needs decide most of our spending