设有关系R(S，D，M)，其函数依赖集F={S→D，D→M}，则关系R的规范化程度至

下列关于道德的说法中，正确的有（）。

A．道德是职业关系的特殊性规范

B．道德是人区别于动物的重要标志

C．道德是现代文明社会的产物

D．道德是共同遵守的准则

简述巴勒斯坦问题的由来和第一次中东战争

Happiness can be described as a positive mood and a pleasant state of mind. According to recent investigations, sixty to seventy percent of Americans consider themselves to be moderately happy, one in twenty persons feel very happy. Psychologists have been studying the factors contributing to happiness. It is not predictable nor is a person in an apparently ideal situation necessarily happy. The ideal situation may have little to do with his actual feelings.

A good education and income are usually considered necessary for happiness. Though both may contribute, they are only chief factors if the person is seriously under - educated or actually suffering from lack of physical needs. The rich are not likely to be happier than the middle-in-come group or even those with very low incomes. People with college education are somewhat happier than those who didn’t graduated from high schools, and it is believed that this is mainly because they have more opportunity to control their lives. Yet people with a very high income and a college education may be less happy than those with the same income and no college education.

It should be noted that people quickly get used to what they have, they are happiest when they feel they are increasing their level, no matter where it stands at a given time. The best formula for happiness is to be able to develop the ability to tolerate frustration, to have a personal involvement and commitment, and to develop selfconfidence and to selfesteem.

Which of the following statements is NOT true ？（）

A. People in ideal situations are not necessarily happy.

B. Sometimes the poor may feel happier than the rich.

C. The richer one is, the happier one may be.

D. Those who are satisfied with what they have often feel happy.